It seems to be mostly an Edge browser problem which occurred when they did some upgrade that broke things, thank you Microsoft. Switching to Firefox has worked for many, and other browsers work as well. Another work around is, once the white bar comes up, if you are on your phone, you can put your finger where a reaction is supposed to be, and a few seconds later the name for that reaction will show above it. If you can move your finger to that text and hold it there for a few seconds, the correct reaction will appear on the person's post. This only works on my phone, though, and not on my laptop. I have an older phones as well and all the reactions show up on it no problem.