Our errors had nothing to do with scheduled tasks or settings set in Web Admins. On the new server we had Multi Mode on for 6.0.1.83, as that was the default, and everything was organized centrally in the Server Admin. Nothing in the different Web Admins. So I assumed when I copied the CFConfig.json from there to the fresh install of 6.2.1.122 that the Single Mode would work similar to the Server Admin in Multi Mode. That did not happen unfortunately. Whilest I hadn’t even looked at the known issues, application-scoped variables started to bleed over in the error-messages between webapps, webapps not working at all because subsystems or pages were not found (FW/1 webapps), and only one webapp would work at a time on the server if they were setup in the same fashion).
See full story here: Session scope not pertained - #17 by Zackster - this issue seemed simple, but exploded with collateral damage, sorry about that…