Long start delay >20 sec after upgrading

[peletiah]

After upgrading my X2100 from factory BIOS to x2100_15122021, I am experiencing a long delay for more than 20 seconds until the BIOS bootscreen appears on the screen. So I press the power button and the screen just stays black for this period until the screen displays anything. I have not experienced this behaviour before upgrading. Is there a setting to change this, maybe a check that could be disabled?