I had a problem guy once, team of 8 on an IT help desk.
Basically had a gentleman’s agreement that they could take thier breaks whenever suited them as long as there were at least 2 people at the desk, or if a major incident was running then they don’t take a break until things settle a bit(as TL I didn’t really care who did what as long as there was sufficient cover.
One guy though would purposefully wander off at these times so I had to introduce a lunch rota on a whiteboard where the guys just pencilled in when they wanted lunch break.
That didn’t go down too well with the whole team but they accepted it when it was pointed out that certain nameless individuals were forcing the situation. (I’d rather the team manage thier own time sensibly like grown ups, personally).
Then problem guy decided to complain above my head that I was forcing him to take lunch at certain times (which I absolutely could do, but this wasn’t the case, I was just making them choose a lunch slot at the start of shift).
Then he started playing the line that I was forcing him to take a break full stop.
So I played the line that I’m not (and can’t force him) to take a break but he would always have the opportunity to take proper breaks.
He then complained about my 3 or 4 x10min smoke breaks per day, so I had to spell out that I don’t take a lunch break.
Never came to anything, Some people are just dicks.
One problem employee can realy be a pain, not so much in proving them wrong, but probably 20% of my time was taken up in doing so and ensuring the rest of the team were treated the same.