Hello Rob, and welcome to the Greenbone Community!
The GSM TRIAL is our demo appliance with a reduced feature set. Not all functionality described in the manual applies for the TRIAL, the Logs menu is one such case.
As Martin wrote, the GSM Trial only has command line generated logs , no options in the GOS Admin Menu like commercial appliances. Anyway, those “Logs” are only more specified journalctl commands anyway. journalctl -f, does give you a full log. If there’s nothing to see, that’s because nothing is happening in the moment. I suggest, stopping and deleting the current scan, starting journalctl -f and then starting a new scan. This way you see everything that happens right from the start.
(Also when a scan “stalls” most time it’s being ignored by something on the target and waits for a time out.)l