tiny ant writing

Every so often, seemingly randomly, my scrivener just disappears all my work, adds a blank space I can’t get rid of and if I back space I can find where I was writing before but it is now tiny ant writing that I can’t read. It thinks it is size 12 and going up/down in font does nothing but mess up more of the ms

It compiles any where from 2- 4 thousand words that are not in the compile section also randomly
I’m using it on windows but this is just not good enough
it has made my ms unusable and I have now lost over a week of work time to trying to fix it

I need help