All available Sims now can be selected for travel even if they are currently not on the current lot.
Fixed in Patch 1.90.375/1.62
If you're still experiencing this issue, please create a new thread.
I'm having this problem too, I can only travel with sims from my household :/
It seems to be limiting the "Travel With" options to sims that are currently in the same area as the Sim who is initiating the travel. In the pic below, my Sim is in the process of travelling to the Spice Festival. She lives in San Myshuno and is neighbors with Miko Ojo. When I first tried to travel, Miko was in the hallway and she was available to travel with on the phone menu. I cancelled the interaction because something didn't look right. By the time I tried it again, Miko had returned to inside her apartment and her portrait was no longer showing as a valid "travel with" option. The only thing that had changed was Miko was in the hallway during the first attempt, but was off the screen during the second attempt.
I tried "travelling with" other sims a few more times the next day. That seemed to be the pattern. If there were any Sims currently on screen + in the area + at least an acquaintance, then they are available as "travel with" options, otherwise they are greyed out.
I am playing on PC, my game is fully patched, and I am not using any mods or CC.
I hope they fix this ASAP. I'm having the exact same problem , since the new update.
