If this were backed by Confluence, I'd be looking at the index for this problem, but it's not, so I don't know where to start.
I'm starting to see questions with answers and comments that don't make any sense as they're out of context.
The one that jumped out at me was found by doing the following:
I went to https://community.atlassian.com/t5/JIRA-questions/JIRA-Cloud-Issues-still-not-shown-in-backlog-after-being-mapped/qaq-p/461051
I wrote an answer, and went back to have a look later, and it all looked fine. Then went to bed.
Got up this morning, and as the site is still not sending me emails I thought I'd check the question manually to see if there was any response, so I clicked "refresh" again.
This took me to
https://community.atlassian.com/t5/JIRA-questions/Dashboard-gadget-to-report-historical-status/qaq-p/116615/comment-id/192145#M192145
So, wrong question, which looks a bit odd, but the url has changed, so I'll happily blame a cache or something.
But, read the question. The question is the same as the one I was answering last night. The comments are from 2 years ago.
That suggests old questions are being destroyed, overwritten with data from new ones.