Beta Windows crashes when entering composition mode (via f11) & writing history doesn't work correctly

Sometimes pressing the f11 key works fine, but other times the program just shuts down. This problem has been happening to me quite recently, and I’ve been using the beta for more than half a month now.
Also, the word count in writing history behaves strange: while writing inside the manuscript, it counts as if I had deleted a lot of words (when I know I haven’t), both from inside the manuscript and sometimes from the whole project.
These two issues appeared at the same time, and I suspect that the writing history failing has something to do with the sudden crashes, but couldn’t figure out exactly what happens.
Any ideas on this?