I have been going nuts for weeks with LR constantly trying to re-publish images I have on my web site. I’m using the Smugmug plugin, because that’s where my web site is, but it seems to a complex LR issue going way back and not limited to Smugmug.
No time now to try to explain it, but when I go to a gallery on my web site (I have over 60!) even if it is a long-since published gallery, the plug-in (apparently at LR’s behest) starts moving a lot (not always all) of the pictures to a un-published (or at least modified since publish) status, and re-publishing them. Publish also hangs a lot. Apparently it got worse in LR 11.2 and it seems now (MAYBE) that rolling back to 11.1 and just letting everything slog through re-publishing will fix it.
There is ongoing discussion about the fix in this thread: https://community.adobe.com/t5/lightroom-classic-discussions/photo-moves-to-modified-photos-to-re-publish-for-no-reason/td-p/12690169/page/2
This thread in Lightroom Queen said a few days ago that Adobe was working on a fix that would be implemented when 11.3 came out. I’ll wait to hear the results before upgrading.