Scheduler Job (should run every 2 minutes) stopps working after hours

A scheduler job,
Atatus: Active; Active From: Always; Active To: Always; Interval: Every2minutes; Job: function::runMassEmailCampaign

Stopped wordking:

Last Successful Run: 13.09.2022 03:26

Currently it is the same day but 09:23.
Staus as above = Active

suitecrm.log does not help me. It mentions the last “Run Mass Email Campaigns 0-24 neu” from 13.09.2022 01:22:01, so two hours earlier:

SET assigned_user_id=‘1’,name=‘Run Mass Email Campaigns 0-24 neu’,date_modified=‘2022-09-13 01:22:01’,scheduler_id=‘dcbe0484-2569-890a-ac04-63186cd1e979’,execute_time=‘2022-09-13 01:22:00’,status=‘done’,resolution=‘success’,message=NULL,target=‘function::runMassEmailCampaign’,data=NULL,requeue=0,retry_count=NULL,failure_count=NULL,job_delay=0,client=‘CRONd61eadcfcba9c5819e0ce84865b91178:17799’,percent_complete=NULL
WHERE = ‘d734490e-f8a2-57a2-1202-631fdb3851e8’ AND deleted=0)

However the log contails several entries with
SOME DATE [18956][1][FATAL] Slow Query (time:0.56159400939941…

I had this problem before.
Tried some Admin repair tools. Did not help.
Deactivated and activate the Scheduler Job. Did not help.
All other Suite CRM Scheduler Jobs run fine.

Finallay it created a new Scheduler that does the same. That then works fine for a while until ist stops working after a few hours of work.
Well, is seems only to stop weorking when there is mails to be sent.
Also it dod work for a few months.

Any help is more than apreciated…

Try running the first query in this post from phpMyAdmin:

This will help you figure out the slow queries. It’s likely that you have an overgrown aow_processed table and your Workflows are just hanging.