OK, 2 months later, and I am STILL in pretty much the same position.....
ie. Job marked as 'Started', but all modules showing 'Not Started'
In January, I continued my usual activity - stopping batches, re-creating them, running them. Over and over. Until suddenly, for no obvious reason, one of them actually starts running.
However, for the first time ever, it actually displayed an ERROR!
Upon investigation, this was related to a known date issue whereby up until SCSM Update Rollup 5, dates beyond 31/12/2020 were not accepted, and errors arose. Well....finally, my request to update SCSM has been completed, so 'that' should no longer be an issue.
BUT....I am back to my original issue! :-(
I can START any job and it will show as 'Running' but all its modules will show as 'Not Started'..........
I followed all the standard instructions for troubleshooting stuck datawarehouse jobs at:
https://learn.microsoft.com/en-us/troubleshoot/system-center/scsm/troubleshoot-stuck-data-warehouse-jobs
Stopping batches. Re-creating them, Starting them again....
However, at a latter stage it just says "If the job completes successfully, go to the next step."
It doesn't give any advice (or even a 'hint') on what to do if the job does NOT complete successfully......
I started the DWMaintenance job last Friday afternoon, and this morning (Monday) it is still sitting there showing 'Running' Status, with all its modules showing 'Not Started' - doesn't look like 'anything' has happened. Over 48 hours later....
As I mentioned earlier, I am reluctant to call Microsoft support, since I have spend 16+hours in the past with a support person who simply reads off the same web page instructions and follows the same steps that 'I' have followed many times.
They don't appear to be 'expert' (or even 'knowledgable') on the system as I have to sit with them whilst they read all the same documentation that I have gone through myself.
I can't believe that I am the ONLY person that is facing the same issue (though I suspect I may be the only one who is reading 'this' message... :-( )
Would be grateful for any new information, or suggestions on where to look next....