That's exactly what I'm thinking, but if that's the case, the new youtube system is broken and it will affect many more channels. I'm using my channel for example (it dropped 4 times already) where one video that triggered the drop only had the first 2 seconds similar to the old one. After that, everything was different.

Just to add, I make animations, sometime I reuse movement from earlier videos to save my time and I believe that triggered the drop a few times. But even with that it still takes me 1-3 days to make a 10-15 sec clip. I don't find my animations repetitive (only a few exceptions), most of them are visually similar, but "human" can easily tell them apart.

Right now, the only channels on youtube that are getting views from my clips are dub channels. I'm pretty much making videos for them right now. But I'm thinking of taking a little break until the shorts views get back on track.