MSI MAG x870 tomahawk POST hang's on B4 for a couple of seconds before booting in windows.

[Yorgo]

Hi !
So I have a issue that pop up recently ! When I boot my pc it takes longer than usual and the POST code hangs a bit on B4 code ! Than pc boots into Windows and works fine ! Is this normal ? Since b4 means USB hot plug I unplugged all USB devices (including the ones on the mobo USB header) and it does it no matter what! MSI supports think it might be my psu or my mobo that is faulty but I’ve sent my pc in a repair shop (cpu was faulty) and they tested everything and everything was fine ! Besides, psu was working fine on my Am4 build! My guts tells me it might be bios or something like that. Is it worth to RMA the board or to worry about it ? (Otherwise pc works fine ! I've had some issue with USB drop outs but its seems to be linked to corsairs stuff)

My specs are :
Mobo : MSI Mag x870 tomahawk (latest bios A30 and latest chipset)
Cpu: Ryzen 7 9800x3d
Ram: Teamgroup 6000mhz cl30 32g
Gpu: Asus tuf gaming 3080ti oc 12gvram (drivers 566.36)
Psu: Corsair Rm1000x shift (1000W)