Sounds like a difference in speed tuning.

Remember the sleep counter reduces only when he's hit, not just when your champ takes a turn.

If you want us to take a further look, please get us a video so we can check it out for a bug.

Cheers 🥂 

Wow the lack of help here is astonishing 

If the link is not sufficient please guide me on how to provide  whatever is needed .

Lol okay 

From what I am seeing in the video you added, there is no bug.

Sand Devil does his AoE and goes to sleep. Aniri revives herself. Sand Devil takes a turn, moving his sleep debuff from 2 turns to 1. Aniri revives Ninja. Sand Devil takes another turn, his second, and therefore wakes up. Then Ninja goes.

No one on your team hits Sand Devil, or deals him any damage while sleeping, so of course his Slumber counter doesn't go down.

You need to speed up your champs so that Sand Devil isn't cutting in front of you and getting both his sleep turns in before you get a chance to go.

That's wrong it doesn't do that below stage 22 

Maybe you should move that to someone with a little more knowledge  about the matter.

Maybe you should try being courteous rather than impatient and rude. 

Also, Sand Devil gets faster every stage so yeah, that's why you're not seeing it before 22. 

Lol

Your issue is clearly shown in your own video. Speed your champs up, they're too slow for the higher Sand Devil stages. 

And yes, as my fellow moderator said, the stats of bosses get more difficult as you increase in level, such as their speed increasing. 

Speed your champs up.

Glad we could be of assistance and have a great day! 🙂 

You are absolutely right I do apologize  thank you for your help