Data Transfers · Scheduling transfers
How do I stop a scheduled transfer from running again?
Short answer: Remove the original entry for that transfer (the first one, which holds the schedule). Removing a later run only clears that run. Clear completed also removes original entries, which stops their schedules.
Remove the original entry for that transfer — the first one you created, which holds the schedule. Select it in Data Transfers and click Remove (it appears once that entry has finished, failed or been cancelled; cancel it first if it's still running).
Removing one of the later scheduled runs only removes that run from the history; the schedule carries on.
Note that Clear completed also removes finished entries, including a schedule's original entry, so it stops those schedules too. If you want to keep a schedule, remove individual old runs instead.
Related: Change a transfer's schedule · Clear completed