PSU trouble(?) in new build

[Benk3i]

Edit: Solved (see post below)

So I posted a build a week or so ago and got amazing help in finalizing the build, but I am now running into some issues which I believe are PSU-related. If this is not the kind of questions for this forum, I apologize and will remove the post. I just got completely stuck now and am having a hard time progressing.

The entire setup is connected, but it will not power up if I plug in all the cables into the PSU. If I skip the 12V ATX cable, it will power up but (of course) not boot to video or BIOS.

If I try to power it up with the 12V connected, I can hear a low thud, which I suspect is the surge protection kicking in. If I just unplug the 12V P4+P4 connector, the system powers up fine, but no boot.

Picture can be found here, tried to describe the setup.

What am I doing wrong?

So more specifically, the components are as follows:
CPU: Ryzen 3700X
Mobo: Aorus x570 Pro Wifi (ITX)
PSU: Be Quiet! 600W SFX-L
Case: Lian Li TU150
RAM: Trident Z Neo 16GB 3600Mhz

 

[Benk3i]

After getting some great help on discord (shoutout to ExplodingWaffle101 and TonyStoneDew) I landed on that there was probably nothing wrong on the build. Tried most of the standard troubleshooting.

Tried changing the PSU the day after, and that did not work. And finally found out that the problem was with the MOBO. Returned my old one without issues and the clerk said that they have had a coule of returns with specifically the Aorus x570 Pro Wifi. Once I plugged that one in, everything immediately worked.

Post can be closed if there is such a thing