HPE DL380 G9 + Dell NVIDIA Ampere A40

Hey guys, does any one know if these two are incompatible?

I have a DL380 G9 with 2*1400 Platinum power supplies, GPU risers and power cable but when I connect the GPU to the system, I get an error about "Server Critical Fault (Service Information: Power On Fault, System Board, AUX/Main EFUSE Regulator 1".

I've tried two different risers but no luck.

I'm not sure if it's just incompatible by default or not. Any help with this would be appreciated.