Running 25.1 on Deciso A10 (AMD GX-415GA)?

[StP]

I still have two Deciso A10 Appliances running in production with 24.7.12.
I have a third, spare unit also running 24.7.12 which I tried to upgrade to 25.1.
The upgrade fails no matter how I try to get 25.1 installed.

I used Clonezilla to create an image of the 24.7.12 installation. Each of my attempts to upgrade starts from this exact same image.

I tried:
- in-place upgrade via GUI
- in-place upgrade via console
- download 25.1 image, copy to empty SSD using Rufus and install that SSD in the appliance, then boot from it
- boot a live system from USB-Stick using a second USB-Stick having config.xml in a /conf directory (like documentation suggests)

In all cases the system starts to boot but hangs after a few seconds.
In most cases the last lines visible in the serial console show that the connected network interfaces switch state to UP.
I think I saw a line regarding PIO being the last visible. Not sure...

So:
Is 25.1 supposed to run on this hardware ad I'm doing it wrong?
Or is this AMD chipset too old to be supported?

Any help apprechiated.