Haven't heard of this yet. 

The shield should should only be going away when Scarab has done enough damage to destroy the it. Also, Scarab steals non shield buffs, conditionally.

Would you be able to record this when ith appens again?

It happens 100% every time. I will do a few more test on a lower level Scarab just to make sure as I'm not a Skarab expert. If I am right how what can I use to record it?

Assuming you're on desktop, Windows button + G should take you to the built in recorder.

Thanks, I think I know what's happening. As the shields get lower Lonatharil replaces one with the A1 shield and then I guess it gets stolen and hell brakes loose and all shields get smashed. Looks like my idea of not using TM control is not going to work on higher levels.

Gotcha. Scarab can definitely be a little finnicky/touchy with speed tuning, but I'm glad you solved it. :)

Just an extra note, maybe the shield wasn't replaced with the A1 shield as it got lower as that contradicts the non replacable part. I didn't take into account my Rotos taking extra turns and losing shield count.