Is there any way to force-delete the snapshot?
Yes, and you may as well make a script of it because it's a frequent problem. 99% of the time is the oldest snapshot.
listlocalsnapshots / ... Output of that command looks like this:
Snapshots for volume group containing disk /:
com.apple.TimeMachine.2020-04-01-122516.local
com.apple.TimeMachine.2020-04-01-132348.local
com.apple.TimeMachine.2020-04-01-143800.local
com.apple.TimeMachine.2020-04-01-153811.local
com.apple.TimeMachine.2020-04-01-183757.local
com.apple.TimeMachine.2020-04-01-193758.local
com.apple.TimeMachine.2020-04-01-203828.local
You just need to copy the timestamp for each line you want to kill and paste it into the next command. Again, usually deleting just the oldest (top) one will resolve related issues.
sudo tmutil deletelocalsnapshots 2020-04-01-090758
If successful, you will get no response (exit 0) in terminal.