Black screen after install (web interface works)

[mfg]

I have installed Virtual Environment 7.0-11 on

1. AMD Ryzen 5 1600AF
2. MSI B450 TOMAHAWK MAX II
3. 2 x HyperXFury 8 GB
4. Corsair CV450 PSU
5. zfs mirror on two 250gb SSD drivez in ZFS Raid1 (kingston and adata)
6. gpu: Sapphire Radeon R7 240 2GB DDR3 128-Bit (299-1E263-500SA)

The gpu is probably the issue, during install i had to

1. press e on install screen and configure nomodeset
2. when i got stuck at "starting a root shell on tty..." i used the fix described here https://forum.proxmox.com/threads/r8168-installation-problems.81644/ and set the card driver to fbdev

ProxMox works well and fast but i have no video output from the graphics card if i ever need to open the shell.
Is there something i can do to similar to the install process to use the fbdev driver?