Battery drain while shut down after BIOS update

Hi everyone, I'm new to this sub and joined specifically to see if others have the same issue like I do. 2 days ago I updated via the Lenovo Vantage app some drivers for Graphics and the BIOS.

Before that update, I never had issues with battery drain while shut off but now within 24hrs of not using the laptop after a proper shut down...the battery is completely drained.

I used before this LOQ 15APH8 another Lenovo laptop (Thinkbook 15G2ARE) which had an option of "Always On USB" in the BIOS that could cause such issue.

However in this LOQ there is no such option. Has anyone encountered this before, what could be the issue?

Thanks in advance.