abrupt disconnect of all devices while booting MacPro

Hello there,

I have a little problem. When I'am booting my MacPro, all my connected devices like USB hard drives, thunderbolt raid and displays are starting as usual. But after 2 or 3 seconds all the devices get a hard and short disconnection. The boot after that crash is normal but don't think, that it's really healthy for my thunderbolt raid to get a crash every time while booting. Before the MacPro, i used a MacBook Pro with all the devices, without that disconnection while booting. So I think there is something wrong with the MacPro.

Maybe it's just some adjustment stuff. I hope you can help me!