Good evening - help!

Today I upgraded our SharePoint 2016 on-prem environment to the January 2022 patch level and ever since we are having trouble with our Nintex Workflows (Nintex Forms & Workflow for SharePoint 2016). It seems to be tied to the Timer Service but I can't absolutely confirm that. For e.g.  We have a number of site workflows, which, if kicked off manually complete just fine.  However if left to the schedule then the workflow bombs out with "Workflow 'x' was canceled by System Account" and "'x workflow' Failed to Start" (see screenshots).  Some of our other workflows are also struggling with specific actions in them such as State Machine.  Some other list workflows, however, are behaving as normal.  We are on the absolute latest version of Nintex for SharePoint, too (4.6.2.40). 

Any assistance gratefully received. 

Thank you.