Hello, I have an issue with tigerwood and penofin stain

Last Summer I was hired to power wash a tigerwood deck and then seal it. The project started off a little rocky we pressure-washed the majority of the tiger wood deck, this was only our third one we've done and we're still pretty new at this. The pressure washing left a few wand marks on the deck so we ended up using Penofin three step process to prepare the deck for our Penofin sealer. So step one we stripped the deck Step 2 we cleaned the deck and step 3 we brighten the deck. We followed the instructions to a T and once we were finished with that we let the deck dry and then we did a little bit of sanding with some 80 grit sandpaper. We then sprayed the whole deck with a Penofin tigerwood sealer and back brushed it. About a month-and-a-half went by and the homeowner contact me and said there's splotches all over the deck where the stain did not absorbe into the wood and a lot of these areas looked like leaves were sitting on the deck which he does have a problem with. We went over there sanded those areas again and restained almost the entire walking surface of the deck by hand with a brush. The deck again looked very nice and finished. Another few months go by and the homeowner calls me again with the same problem. I'm curious if anybody else has had this problem? When I contacted Penofin they didn't really seem to have too many good answers for me right now. I told the homeowner what I would like to do is wait until summer when the deck is completely dry and look at it again and get Penofin involved and see if anybody has a solid answer for us. I want to make sure this customers 100% satisfied. I'm sure he's pretty aggravated that we're still dealing with his deck not being perfect as it should be. I have only been doing decks for about 3 years and hardly ever do tigerwood decks, but this is a first for me. Any advice on what I can do to correct this problem so I don't have to keep going over there every couple months and resealing the deck would be great. I have also attached before and after photos. I have not had this problem before. I have used this 3-step cleaning process on cedar wood on my own personal deck and have not had this problem. Also, both times I have sealed this deck it has looked amazing when I was finished.

After reviewing the pictures and your post I will give you my best response which some you may not like. First, Penofin and Sikkens, in my opinion, are two products that should not be sold to end users. Penofin does not work well in the Northeast or Northwest and many distributors have stopped carrying this product (hint, hint). Penfoin also does not like humidity, basically needs ideal conditions. I have even seen seasoned pros have issues with these products. Both products MUST be applied correctly and maintained correctly or there WILL be major issues. These issues usually mean black spots, dark areas, mold and mildew issues. When there are issues and the product needs to be stripped off these products do not strip easily. The manufacturers do not even make a stripper that removes there own product effectively. I would like to start out with that Tigerwood is a very dense hardwood, as are all the Brazilian Hardwoods, that DO NOT allow for the same penetration of the products into the wood. Penofin works well on mahogany because it isn't as dense, with Exotic Hardwoods this means that you will have to "work" the product more when applying.
Let me start with the cleaning/stripping process, why did you strip and then clean? Were you removing another product from the wood surfaces? When stripping a deck you should use a sodium hydroxide based stripper which after rinsing MUST be rinsed well before applying the oxalic acid. If it is not well rinsed you could form a salt which will leave the deck lighter or cloudy in areas. These areas will be accentuated when sealed or stained and the coating will fail in these areas quickly. When applying the oxalic acid based brightener, which I recommend, because it is faster acting and you can see any missed spots or problem areas almost immediately you want to cover every inch of the deck.
Next, you mentioned sanding and do not know why this was necessary? When sanding a deck you are changing the porous surface (ideal) to a smoother surface changing the characteristics of the porous surface. It is important to wait approximately 7 days or so for the wood to "weather" and allow for expansion and contraction to occur. This will reopen the pores or cells of the wood to better accept the coating. Applying a coating immediately after sanding will not allow for proper penetration and coating failure.
Now regarding the sealing or staining process of this wood. Despite Penofin's or anyone else's recommendations the best applicator, in my opinion, is a lambswool applicator. It is extremely important to not over apply oils to these species of wood. We will apply to 4 boards and then before going to the next boards re-wipe the first 4 boards and not leave any excess. It does not matter whether you use the one coat or two coat formulas once the first coat dries the second coat does not bond well and the second coat sits more on the surface of the first coat. Three things can happen when this occurs. One, the second coat will not get into the wood properly and will "peel" away from the first coat or away from the wood. These products are NOT meant to peel which means you have a failed coat. Second, the oil never gets into the wood and it remains somewhat tacky or sticky. In this case, or for any other wood when this happens, your first remedy should be to wipe all surfaces with acetone. Third, when the oil does not properly get "into" the wood you will have accelerated mold and mildew issues. Also, it is really important to use a moisture meter when applying Penofin to insure coating success.
Looking at the pictures you have inconsistencies and surface failure. The first rule of thumb is NEVER apply a good coat over a failed coat. This means this deck needs to be stripped and brightened to restore the appearance of the wood surfaces. The best way would be a sodium hydroxide based stripper with butyl added to the mixture. allow at least 30 minutes for dwell time and rinse. Depending on surface and ambient temps. you may have to wait up to an hour if multiple coats have been applied for the coating to begin melting. Then re-wet surfaces or apply oxalic acid brightener while the wood is still wet. Once surfaces are dried you will probably have to do a quick once over with the floor sander. Let weather for the 7 days or so and re-coat.
Regarding coatings, you should look for a product that is easy to maintain. This means going back it should be easy to clean and re-coat. Penofin has to be reapplied at the same rate as other penetrating oil based products without all these issues. You would be better served to use Messmer's, TWP, Bakers, Grey Away (just to name a few), or a few others that are made with long, penetrating oils.
Hope this helps and if you have more questions or comments just fire away.