Most times it clears for me after a couple or few attempts, but if it doesn't, I just give up (LOL) and give a thumb's up, which is a reaction I rarely have given otherwise. Another thing you can do is piggy back on someone else's reaction, but of course, the one you want has to already be there for you to do that by clicking it and adding yours to it. If you are the first or the one you want is not already there you are out of luck...