First, verify if the uxbck process is present in the system, in case it does and has not finished, cancel it.
After that, the Job should Abort.
It is likely that a stop / reorg / start of the node is necessary to restablish the service.
In case that still does not fix the issue, using the command mode is the best solution for this.
To suspend future launches (The Jobs will be disabled, re-enabled to run at a later date and may run if it is still within their launch window. Otherwise the Job will go into a Time Overrun.):
uxhld FLA ses=* upr=* mu= nseq=*
To delete the future launches (The jobs will NOT run.):
uxdlt FLA ses=* upr=* mu= nseq=*
To stop the running jobs (The jobs will be abort, the post Uproc will not be executed):
uxend CTL ses=* upr=* mu= nseq=*
Fix Status: No Fix