Unfortunately these remotes only stay waterproof for a very short time. The epoxy potting mix they use expands and contracts due to the heat and cold and then the water can get down between the wires and the potting mix. It also happened recently to my screen. I hadn’t been having the screen issue but had read many topics where people were getting this as an issue. Luckily I saw mine straight away and when I went to investigate the black potting mix that was on the back of the screen basically fell out. This allowed me to dry it all out over a few days. Then (and this is bloody fiddly as the screen wires are very short) then I dremelled a small angle off the potting mix so that when I put it back together I could then fill the edges with some silicone potting mix which is flexible and will hopefully bond better to the screen case. Thus far this has worked successfully.
I think if Flipsky used a process similar to this and epoxy potted the first layer and then used silicone potting as a second outside layer they would have a far better product. I have covered all the wire entry points and now that screen fix and the remote is working well. I only use it in salt water so a decent testing ground.
Just my 2 cents worth.