The post was trying to promote a (most likely malicious) unofficial file explorer app and it was in no way related to your post, just trying to get victims, if you happened to install it I’d advise uninstalling it and making sure you didn’t give it any permissions that would expose any private information of yours.
Also as for your bug report, do you by any chance teleport the Item Placers? I found this bug post which seems to be experiencing the same issues as yours (Item Placers are invisible but the interaction prompt still shows), If you believe this is the same Bug I’d recommend upvoting theirs.