Reporting part-time earnings while on benefits after 12 years as a retail manager

I picked up part-time shifts as a retail manager and I am confused about how to report them. Sometimes my paycheck is late by a week. Did anyone get an overpayment notice from a mistake?

The claimant handbook has worked examples for part-time pay. Mine was clearer than the phone line.

I estimated and then checked my pay stub. When there was a small difference I wrote to the agency to correct it.