>>290407527
No that's not normal.

It deleted the bag as it wasn't joined into the model for whatever reason, that's my best guess.

One way you could probably avoid it is by selecting the bag first and then your character by using [SHIFT] and clicking on it, after that you can hit CTRL+J to join it together with your character.
Then you could hit fix model? Maybe that'll work.
I do highly recommend you watch some Blender basics at least on hotkeys to get the hang of the program.

If you have issues with anything, search it up and you'll likely find a solution.
https://www.katsbits.com/codex/join-meshes/