Ideas
I just had a sim join this career for the first time. I followed her to work, picked up my first assignment, completed it, and then was instructed to click on self to travel (back to the office), but the option was unavailable because Sim is at work.
I don't use mods and CC hairs are disabled.
Her assignment was to pick up lost souls and close fissures. While on the lot, I had her do all of that and I also reached into a couple fissures and showered in the rain twice because apparently this is dirty work. Oh and I had her forage for food and eat some blueberries and apples while on this lot. The lot is on some kind of island/water in background and there seems to only be one selectable building that looks like a church when I zoom out. I'm not sure which world this is, but it isn't how I pictured the netherworld.
Update: The next day, I joined my sim and we went to strangerville for the assignment (so maybe it's certain lots that are bugged?) and I quickly grabbed the souls and closed the fissures without doing anything else and when I clicked my sim, the option to return to office was there so I didn't experience the glitch on the second day of work at another lot. After work, my sim leveled up to lvl 2 in the grimreaper career.