App Layering - Stuck Tasks or new tasks hang at "pending" or "stalled"

Tasks won't progress, appear as stalled. New tasks sit at "Pending" From maservice.log: 2021-01-11 09:10:25,575 WARN 20193 UnitOfWorkImplemen: Transaction is implicitly being rolled back at Uni.Appliance.PersistenceLayer.UnitOfWork.UnitOfWorkImplementation.Dispose 0x00025 in :0 at...