It seems a common problem to get water seeping into the arm with neoprene, particularly the left that you are using the inflater. Someone gave me a tip on Sunday, to pull the wrist seal up the arm slightly and then pull the sleeve over it, to form a cuff. I tried this and, on the second dive, I finished with my left arm thermals slightly damp rather than wet - which was probably from the first dive. So simple, just have to remember to do it before I jump in.
They should have shown you this when you were taught drysuit and having latex is not an excuse, courses are meant to explain common variants The seal on neo is often too long and is commonly left over the edge of the wrist. This not only stretches the end but reduces the contact area on the wrist proper creating a slight void right where the veins are. Like you've found the seal is pulled right back so it's on the wrist proper and any excess is formed into a cuff. If using wet gloves these are now tight against seal and the end tucked into the cuff
