I have an unpublished snapshot with plenty of changes.
But, I didn’t make these changes… (and for sure, I haven’t been hacked).
Any way, in the doubt, I don’t want to publish it.
How can I delete the snapshot?
Because if I do changes now, it will publish the old changes + the news ones.
Did you check the Changelog tab in Tag Manager? There should be an option to look into current unpublished changes and review them.
If you’re sure you didn’t make any changes - you could always revert to the last snapshot, which will discard any of unpublished changes.
Here is an article that goes more in depth into changelog: