Last week (Sunday to Sunday) I had a repo running a lot of cron workflows 24/7. After like 4 or 5 days I exceeded the free limits (Pro plan) and so set up self hosted runners.

After like day 2 my workflows would take 10-15 minutes past their trigger time to show up and be queued. And switching to the self hosted runners didn't change that. Happens every time with every workflow, whether the workflow takes 10 seconds or 10 minutes.