Didn't realise I accidentally cleared the tag box due to a write conflict. I used Edit Mode so when I set the parent my tag box was empty and changes were made before I hit enter so I ended up removing all the tags and I didn't even catch that as I was finishing tagging the rest of my posts. My bad. Seems it happened to the other posts as well on a smaller scale, only this one had everything removed. I was only told about an hour later that it happened so I couldn't undo it myself. Now it looks like vandalism.

First time I've hit an oopsie of that caliber without being fast to fix it myself... RIP edit history. I didn't undo the original tag removal for this post but I fixed the ones that happened on the other posts and also added some of my own tags to this one (missing stuff).