[FIXED] Fatigue Debuff doesn't go away for Low Fitness Sims

This happened to me to me too, I had my Sim take a bath and even took her to an Onsen bathhouse and nothing removed or decreased the Uncomfortable moods. At the end I decided to save and go back to my main Sims page, then went back to play with my Sim and the moods were gone. I hope this helps!

I’ve had this problem too. Go to Manage worlds and it clears the buff. 

Product: The Sims 4
Platform: PC
Which language are you playing the game in? English
How often does the bug occur? Unsure, just had it happen for the first time
What is your current game version number? 1.96.365.1030
What expansions, game packs, and stuff packs do you have installed? all expansions except high school; all game packs except for weddings; all stuff packs.
Steps: How can we find the bug ourselves? My sim used a workout machine then jogged, and the next day he had the usual moodlets for very uncomfortable after exercise. (sore muscles/fatigued)
What happens when the bug occurs? The Sim will get the fatigued debuff but it has arrows indicating it's getting worse? Pointing up vs down.  Nothing helps except going to the manage world, then coming back.
What do you expect to see? The fatigued debuff being removed with the bath or rest and have a countdown.
Have you installed any customization with the game, e.g. Custom Content or Mods? No
Did this issue appear after a specific patch or change you made to your system? Unsure

I've had this happen to a teen as well.  She has 9 fitness and her brother who is also a teen can jog to clear mind just fine, but as soon as she jogs to clear mind she'll get that weird fatigue buff with no timer that doesn't go away.  No other exercise will cause this to happen with her, just the jog to clear mind.