I am running into this issue with my current save. My sims work performance meter seems to get screwed up when:
A. I have moved the sim from another world through marriage or move-in method and they had a job and boss there already. I was getting zero job performance. Went back to the world to quit and did it but the boss was no longer listed in that town and continues to show on her relationships panel as boss (but grayed out). She has a boss and coworkers in her current town.

B. One my sims is a workaholic and traveled to Riverview. She autonomously started working from 'home' using the computer while there. So she got assigned a boss in that world as well. Now it shows in her relationship panel also. I'm not sure if it means she has a job there also or not. Her job performance is also slow in current world (but not totally stuck like person in A.)

Is there any way to fix or avoid these issues? I am now careful to always have them quit their job before they change worlds but the bosses still show and work performance is still not working right. I am populating my world with people from other worlds, so this is going to affect a lot of my sims.

Sims picking up co-workers and bosses in worlds where they never really worked (e.g., on vacation) is something I've seen quite often as well. Teens and children will also seem to pick up "friends," well acquaintances anyway, at schools they never attended. These bogus relationships can be zapped away with a ctrl-click if the RelationshipPanel mod is in play.

The job performance issues seem odd. Perhaps see my comment about the version of SP and its add-on modules if you are using it.

Sounds like you need to use fix homeworld in debugenabler. It should fix the performance but not sure about the boss. Let me know.

I have done this but she is on maternity leave unfortunately so I will have to wait a bit till I can report back with results.

Okay, finally I can report back on this. I fixed the homeworld but it did not help. Then I remember what Igazor said on the other thread about the sim being in a caste that did not have career progression turned on. And that was the problem. She was a pre-made sim from Hidden springs that I moved into the household so her setting was probably set to that by the game. She was promoted now. Thanks for your help Chain_Reaction and Igazor!

I have two follow-up questions:

1. I made a change to Active Family caste so it never blocks career or skills. I set the caste priority to 100. What's the actual limit of caste priority?
2. Does fix homeworld only work on the active sim or all sims in world? It reports numbers but I don't know what they mean.

Wish I could get the time back that I wasted trying to figure out why my sim wasn't progressing at all in his career until I finally noticed the SP setting, but glad my reporting it helped sort this out (somewhat indirectly).

1 - Subject to confirmation from Chain, there probably isn't a limit except for whatever astronomically high number that integers can go and still be recognized as such by the game. But unless you have castes with priorities 10 through 99 in play, 100 seems kind of like overkill. The caste priorities are only relevant relative to each other when and only when two or more castes provide conflicting settings for the exact same option, it's not that a higher priority setting alone will change sim behavior.

2 - If run on City Hall, should be all sims in the world. Not as sure about running it on a sim directly, but it always looked to me like that did the same thing. What kind of numbers are being reported?

Actually with her, it was not in a caste but in "Sim Options" - I don't think any caste can override that, so my caste may not work, now that I think about it. I wish there was a way to see a 'composite' of all options from the castes/sim/household but that's probably not possible as they may have multiple values. I also had to make another caste to make sure everyone in the town aged because not everyone was aging. Thank goodness (and you all) for SP, which let me fix it, otherwise I would have given up on this game long ago!

When I do fix homeworld, I get a message like "Fix Homeworld Corrected: 0" or sometimes in the past, it has been more. So I guess that is the number of sims for whom homeworld was fixed.

PS: a lot of these options etc. are probably set because my town is being (slowly) populated with Sims from other worlds. That's how I am doing it - so they may have issues that other 'regular' sims don't run into.