Boot Problems with new PC

[SimiZeroDeux]

First my specs:
CPU: Ryzen 7 3700x
GPU: MSI RTX 2070 Super
MB: TUF GAMING B550-PLUS
RAM: G.Skill Trident Z Neo (2x 8GB DDR4-3600)
DATA: Adata SX8200 Pro M.2 SSD +(2TB Seagate BarraCuda)
PSU: Corsair RM750 *2019*

The Problem:
So, the Computer once it is booted it works perfectly fine. But the Problem is, sometimes it just will not start, those times it goes into this weird state where the motherboard error code for the VGA lights up white and the GPU fans are at 100% speed. Bios and all this are up to date. The strange thing with the GPU is, that it was tested before I bought it, so it should not be the problem.

 

Thanks for reading.
I hope somebody has a clue, a trick or a solution for this problem
Simon