No it's enough to visit the adventurer's guild in adult age during evening, however in the previous versions it could be (randomly) skipped, and it shows up once

So if you have visited the adventurer's guild once in a past version and you don't have it enabled, it's likely that you could have had bad luck, and it was instantly discarded

the only way would be to resume a save from beginning of adult age. I tried several times now and it always unlock (I made sure this time!!).
To be more clear: you have 30% chances of meeting him (unlocking the route) every time you enter adventurer's guild at evening.
Before, that happened ONCE. So in my playthroughs I was lucky and always got him, while other people missed him and then he won't show up again. Now it works, it's enough to try visiting 3-4 times and it will unlock
