Having a problem with my Samsung Note on Facebook. When trying to type or go back and correct the cursor jumps all over the place. Usually to the middle of whatever I'm typing and when I try and set it for the end of the sentence it still jumps back to the middle. I usually have to escape out to the save screen and then get back in. I thought it was just gboard but it's actually happening on the Samsung board too.
I've been having the same problem and it was driving me crazy. I tried everything. I finally figued it out. I turned off predictive test - VOILÁ! It worked! The problem only seems to occur with Facebook, so I just turn it off for Facebook, the turn it back on for everything else.