With posts being shown again after being saved, or even just after a browser Web page refresh, I'm now unable to unsave them (with Microsoft Edge, version 131.0.2903.63, on Windows 10) by clicking the "Save/Unsave" left side icon (shown within a blue oval in the image below). For example, this failed with 4 posts that I've tried from my saved list, with the developer console of Set of all versus some showing the following:
As shown with the right side green rectangle, the last 3 error messages, i.e., issues with jquery.min having a return code of 400, each occurred when I tried clicking the icon to unsave the post.
However, this does work properly if you click that icon to save and then unclick the icon again without refreshing/reloading the page. Unsaving a post after the page is displayed again, or even just redisplayed, has been working for me as recently as of several days ago, so this appears to be a recent issue.
Fortunately, in the Profile Saves list, clicking the right side item menu and then choosing the Unsave option does work, apparently for all of the posts. Nonetheless, I would appreciate also being able to use the icon on the posts at any time.