Don't thank me yet, we didn't figure out what's going on in your case. 
If you manage to leave turn-based mode, that's a sure sign your restealth attempt succeeded. It means you left combat, therefore detection has dropped below red and no enemy knows where you are. If they didn't detect you automatically in the first place, they shouldn't detect you automatically afterwards. The stealth/detection formula does not change after being detected.
And vice versa - if you can't leave turn-based mode, that means an enemy knows where you are and that's keeping you locked in combat. (Well, enemies also drop aggro if they can't get to you within 4-5 turns, but that's a different thing)
The ability you are using to restealth matters a bit. There are two slightly different ways the incap/freeze effects allow restealthing.
Some effects drop detection to orange immediately, others require distance and time to slowly drop detection from full red eye. Naturally, the slow-acting effects are easier to use if they have long duration and range.
If you're using cryostasis, you should have easy time. It's one of the few immediate restealth abilities.
This could be a case of me not understanding the mechanics, so let me try to suss this out. So, if still turn-based, someone is detecting you. So let's use your example of Cryostasis. You are in combat, and you freeze an enemy. You stealth, then run around the corner out of LOS. But won't turn-based mode stay active for multiple rounds regardless? That's been my experience, that the stealth button may be available, but that doesn't necessarily mean it will clear aggro. Whenever I've done this, the turn-based mode stays active for multiple rounds, and since I get out of LOS asap, I never know if aggro is cleared or not. Are you saying that a successful stealth from all possible enemies will immediately drop out of turn-based mode in the next round?