I have a strange behaviour of an own scheduler task in a TYPO3 8.7.45:
The task should get covid-data from RKI. and as there is no fix time when data is updated the task should run every 15 minute. it compares the received data with the last fetched data (there also is no timestamp in the data).
In case the data has changed a new record is stored with current timestamp to identify as the newest data.
This works in general.

The strange behaviour:
every now and then the repeating scheduler task is deactivated without any error occurring.
I even added a second task at different times and both are deactivated after a while.

What could be the reason for this deactivating?

There are multiple tasks active (from every minute to once a day) and no other task becomes deactivated randomly

I also inserted a log which shows:
the task runs correct and it exited as expected:
after the daily update it logs multiple times 'got already' (as it has data for this day already) and then it stops.
there is no initial log entry without exit log entry.