Best display setting for x86-64 emulation (Firefox crashes) ?

[freebrowser1]

Describe the issue
First: this is not a macOS issue but a Ubuntu issue as Ubuntu is the guest OS.
Firefox on Linux crashes after startup with errors like :

user@Xubuntu:~$ firefox 2>&1 | tee err
ExceptionHandler::GenerateDump cloned child ExceptionHandler::WaitForContinueSignal waiting for continue signal...
13089
ExceptionHandler::SendContinueSignalToChild sent continue signal to child
Exiting due to channel error.
Exiting due to channel error.
Exiting due to channel error.
Exiting due to channel error.
Exiting due to channel error.
Exiting due to channel error.

I run Ubuntu 22.04 x86-64 in emulated mode on an M1 Macbook Pro. It works relatively slow which is to be expected, but workable as I set 'Force Multicore' and 8 cores. For other apps I have no problems with the x86 emulation, it just works like on a native, but slower. The only app which has problems is Brave Browser which in some rare cases issues 'Aw Snap !' but clicking on reload just reloads the page normally.
Maybe this problem has nothing to do with UTM, at most with improper display settings.
I first looked on similar issues on UTM and read that setting another display settings like 'virtio-gpu-pci' or 'virtio-vga-gl' and to disable the GPU.I tried that, but FF still crashes.

Which display setting is the best ?

Configuration

• UTM Version: 4.35
• macOS Version: 13.4.1
• Mac Chip: M1Pro
• Guest OS: Ubuntu 22.04LTS x86-64