Death Feigning Beetle Shaking

[MoeMillipede]

Yesterday, I recently received 5 beetles in the mail and one of them was really black and was trying it hardest to stand, it would later turn on it back and start shaking (Video for it). Today, it seem to be doing better after giving it sugar water. No more shaking and able to stand on it own but not moving much, any idea what going on? I'm currently quarantine it from other beetle for now.

 

[Smotzer]

If you flipped it back upright would it flip back over onto its back, repeatedly?

 

[chwonce]

If you flipped it back upright would it flip back over onto its back, repeatedly?

I'm currently seeing this exact problem right now. My BDFB is refusing food, shaking and will keep flipping itself over. She was allegedly captive-bred and I recently bought her.

Edit: Looking into this, seems like the only feasible thing would be pesticides- only problem is, most recent thing she's eaten has been bug burger, nothing else. It's been a few days since that last feeding as well so nothing recent, either. I guess I'm just unlucky.