Missing symbols?!

Opened up a Sketch file today that I’ve been working on for a while. I had about 100 icons as symbols but today there are random ones missing, about 40 of them. I definitely did not delete any. Thankfully I have an older version saved but this is worrying! Any ideas?

MacOS 13.3.1
Sketch: 96.1

in this screen shot on the left are the icons on the file with the issues. On the right are the icons that should have been there.

Any insight appreciated, thanks!

Oof, that doesn’t sound good. We’re not sure what’s going on here. Do you mind if we take a closer look at the document? You can send a copy to productsupport@sketch.com

Hi Jonne, thanks for the quick response. Sure, I’ll send over now.