Lenovo P520 with ATI Radeon PCI (not PCIe) VGA GPU display issue

Hi,
I am trying to boot TrueNAS scale 24.10 on Lenovo P520 with ATI Radeon 9250 PCI (not PCIe) VGA GPU card connected to Acer monitor, initially the display works fine, but after some boot messages the boot process stops, screen goes blank. On TrueNAS 24.04.2.3 the display is garbled.

Please advise.