Textures stuck on low resolution in UE 5.4

For those who are still having issues with this. This is in my opinion, the easiest solution there is. It definitely has to do with the Oodle ID for each texture.

To fix all textures in a batch process, select them, right click → Asset Actions → Edit Selection in Property Matrix

Then after that, go to the section Compression → Compression Cache ID and give any of the fields a random value. This will force all textures to regenerate a cache value and fix them.

I hope this helps someone.