Hey @be_Berlin, in general, we use a race condition safeguard to ensure that two rows don’t end up with the same ID.
If you’re seeing a large number of skipped IDs, it likely means those IDs were assigned, but the row creation process failed — so the rows don’t appear in the table.
Do you have any automations running?
I’ve added more details here: Custom field autonumber skipping numbers - #6 by olgatrykush