Cheap eBay RC Drone With 4K HD Camera WiFi FPV Foldable Quadcopter

I just noticed how cheap these have got, so I figured I'd order one. So far much more durable than the micro drone I bought years ago. After getting clogged with dust and many crashes it still flies... well sort of. It will no longer get very high above the ground. I took it apart and found the lower PC board loose, so I snapped that back in to no avail. Watching the videos it looks like the right rear blade and motor might be having some issues. Anything else I might check?

I got the sound track from https://pixabay.com/music/
The first track is Groovy Ambient Funk by moodmode and the second is Movement by SoulProdMusic. The voices were from Mimic_3.

And here is the eBay listing (if it's still up)
https://www.ebay.com/itm/285790187639