With the most two recent updates, 22.2 and 22.3 it's been impossible to edit caption text. It takes a dozen times for my to just change a font and no matter what I do, I cannot physically edit the text. I click to highlight, type 1 character and it just kicks it back to the original. I can however delete things.
I've reverted back to 15.1 and seems to be working fine now.