I believe that the Arista film is re branded Fomapan, ny main go to film, and sometimes, not always, Stopbath can cause this problem with Foma films, the emulsion is very soft when wet and sometimes is sensitive to acid stop, I suggest that you use plain water at 20 as a stop, use 3 changes of water,inverting the tank 10 times with each change of water, also, I would never use a film wiper with any film, but especialy with Arista/Foma film, with 120 just hang up after a shake of the reel, the film will dry fine, with 35mm take a sheet of kitchen roll and wipe the shiny side of the film twice, do not touch the emulsion side.