It’s surprising your performance improved after turning off QPFRADJ.
Before randomly changing the MAXACT in any pool, verify the average amount currently running in each pool.
Type WRKSBS and note which subsystems are running in each pool.
Press F11 to view the total number of active jobs in each subsystem.
Based on those totals, compare to the value for MAXACT in the WRKSYSSTS screen.
If any of those values are too low, some jobs will go to INEL state.
Increase the value to a number above the total you viewed in the WRKSBS screen.
If they’re already above the total, that is not your issue and increasing the number won’t help but be sure to use the average for the day(s).
You should start collection services to view daily reports of where the performance problems are occurring.