After reading all the threads I could find here, not wanting to have to restore from a
backup because of some changes and not having the cell phone options available as some seemed to, I messed with various cheats for a while and finally got this bug to clear. I didn't see this solution posted elsewhere, but apologies if I missed it.
I used a combination of testingcheatsEnabled true and the Master Computer mod. Of course make sure you save a
backup copy of your town in the loading screen and
backup your game overall.
1. Make active a Sim that did NOT move in during the stuck move.
2. Shift-click the Sim that DID move in and select Object...Delete it. Check that the bug has cleared (selecting the cell phone and seeing if Travel and Move options are still grayed out, for example). If you moved in multiple Sims and the bug has not cleared when you delete one, exit without saving, return and try again with another one. For me it was only one of the two moving in that was bugged.
3. Now click the active Sim, go to Master Computer...Household...Add Sim...and select 'Type of Sim'. From there select the type 'Dead'. Find the Sim you just deleted, add it, and your household should be unstuck with the new Sim in place.
I tried resetting Sims, lots, even the whole town, and moving people around households and re-adding them, all sorts of steps, and this was the only path which worked. So here it is as an alternative to the
backup option for those who wish to avoid that.