Blankscreen when starting Proxmox installation

[ThatLinuxUser]

First of all: I'm not a Proxmox pro (this is my first time), neither have I ever installed any other Linux distro (until now) and neither am I a fancy terminal/grub wizard. So please be in your guidance for me and many other as detailed as possible

Here are my hardware specs (all of them are tested, they work properly):

• Ryzen 5 5600G
• 2 x Kingston Server Premier DIMM 8GB, DDR4-3200, CL22-22-22, ECC
• ASRock B550M-ITX/ac (newest BIOS-Version L3.44)
• Lexar NM790 4TB, M.2 2280 / M-Key / PCIe 4.0 x4 (no... HDD's weren't preferable either, didn't want to go through the "HDD-headache" for that amout of diskspace)

For:

• Proxmox 8.2 (https://www.proxmox.com/en/downloads/proxmox-virtual-environment/iso/proxmox-ve-8-2-iso-installer)
• Debian 12.6 (https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-12.6.0-amd64-netinst.iso)
• Debian 12.6 Live KDE-Option (https://cdimage.debian.org/debian-cd/current-live/amd64/iso-hybrid/)

As you can tell from the title, I'm facing the popular issue that when trying to start the Proxmox installation with ANY of the available options (same goes for Debian), the screen will just go blank / the monitor suddenly doesn't seem to detect any source. I've scouted through many possible fixes and NONE OF THEM helped me, which only leaves me to ask here for more solutions. Please mind all the solutions I've already tried:

• In general:

• Reformatting and clearing the usb-drive multiple times
• using different monitors (ASUS VE248 |SAMSUNG 24" Curved Gaming Monitor Odyssey CRG50 LC24RG50FQRXEN)

• For Proxmox (I've found also some other fixes, however for those you'd have to be already in the installation wizard, which doesn't apply to me as before the installation could really start it just goes blank)
  • "nomodeset" parameter (in the grub-editor)
  • BIOS settings: CSM (turned off), IOMMU (turned on)
  • "quiet splash=nomode"
  • "set gfxmode=1680x1050,1680x1050x32,auto
    set gfxpayload=keep" (in the grub editor)
  • BIOS settings: TPM and Secure Boot (turned off)
  • trying to install Proxmox on top of Debian 12.6 (look down at the next applied steps)
    
• For Debian (to install "Proxmox on top"):
  • "nomodeset" parameter (in the grub-editor)
  • installing the live kde-version of Debian 12.6
  • (i may have forgotten some other fixes I tried)

The only possible fixes I have in my knowledge arsenal are the following, however I'm not trying these unless there is absolutely no other way / recommendation / way by you guys. I first want to stick to regular fixes before messing around on hardware level:

• Inserting Proxmox on the 4TB SSD by inserting it into another computer (my gaming rig: "ryzen 7 5700x and rx 6650xt" would be the only option, however I doubt this would affect anything because, as my server rig does, it uses AMD graphics (drivers), which is mostly presumed to be the cause of this issue)
• Using a different USB-drive (this is the last and only I have, all the other are janked up)
• (I may have forgotten some other fixes I could try)

Acknowledging that the same issue somehow also occurs with Debian installation, it either has something to do with some kind of hardware driver or a generell hardware issue. (I'm for sake of complexity excluding the second option as I've already tested the components and they should all function correctly). I'm baffled and clueless on what to do next. Please help me