See: Preemptive thread weird behaviour with DoEvents and Thread.Sleep
Thread.Sleep, Thread.SleepCurrent, and DoEvents are quite messed up right now in 2024r3(.1), Although, from my testing, this is only the case with 1 or more preemptive threads active. I won’t be using 2024r3(.1) until threading is stable again. I already have issues with 2024r2.1 and don’t need to add any more. (Offending code in 2024r2.1 does not seem to be any different in 2024r3(.1) so probably not fixed)