Need some help regarding a HP Elitebook 840 G5

Hey Guys, so we have got 100s off HP elitebooks 840 g5 but they all have a custom splash screen. tried to use BCU and also turning off the custom image in the bios boot settings but the custom splash is still there could anyone help me out please

Is it bios splash or windows splash?

Bios splash screen since it still shows without nvme in