Proof:
My version: https://scratch.mit.edu/projects/1318187760/
@linedancingninja's version: https://scratch.mit.edu/projects/1315294469/

In both versions, all of the sprites were backpacked and reimported. The issue does not exist for sprites that weren't imported with backpack.
Try sending this discussion to the Scratchteam if possible, but please don't harass or yell at them in the process.

This is my 3rd discussion I've ever made, so I'm sorry if it seems confusing or low-quality.

PLEASE FIX THIS

It's happening to me. There is too many of these bugs thanks to the editor updates.