have the computers run an inventory update since the block was removed?

run sudo jamf manage to update framework

10 or 15 minutes and that should hit all machines. I haven't seen a connection to 'jamf manage' or 'jamf recon'.

If it still has trouble, that data is saved in '/Library/Application Support/JAMF/.blacklist.xml'. I supposed you can delete it. That file must be read at boot or something as deleting it didn't unblock any apps for me, so a reboot may be necessary.