Changes being overridden

I am having this problem with several different WP sites, so it pertains to various (but fairly recent) versions.
I make edits, but by the time I publish (or save draft) them, previous content appears. For example, I might go to fix a typo, and then I re-publish immediately, but the change does not appear. Or, I might make several changes in the post, but not all of them end up being made.
I have I thought that this might be related to auto-save, but I’m not sure. What I do know is that prior to two or three months ago, I did not have this problem (and I have been using WordPress extensively for a couple of years), and now it is happening frequently. I am aware that auto-save can be turned off, however I’d prefer not to do this at the code level, where it would be over-ridden by upgrading to the next version of WordPress. I have seen a couple of plugins that manage this – wondering if this would work, or open up unforeseen side effects.

thanks for any advice.