Windows 10 having issues after Windows Update issued firmware update

A day ago, on 2/22/21, Windows 10 told me that it had to update. So I told it to update and shut down. Everything seemed to be fine. It updated and then shut down. Later, I wanted to check if my laptop was fine after the update. That’s when the craziness began.

When I turned on my laptop, it took me to the GRUB menu (I have a dual-boot setup with Ubuntu 20.04 and Windows 10), and I selected Windows 10. Afterwards, it told me to wait while it installed a firmware update with the boot logo visible. The screen disappeared but came back a second later with the same screen as before, except now with a progress bar. I expected it to do something, but it rebooted, and I selected Windows 10 again. It took me to my login screen. I tried to sign in with my fingerprint (my laptop has a fingerprint sensor) and then told me I had to set up my PIN. I was confused. Prior to this, I had a PIN and fingerprint login set up. So I went through the process of setting up a PIN. In the middle of the process, it stopped and told me that it needed an internet connection. I closed the window and it took me to my desktop, where it told me that I had to sign-in again to my school account (it’s not a school machine, so I can’t take school IT support. I only use this device for checking my email and doing work when my school machine doesn’t do what I need to do as well as this one). After I signed in to my school account again, I was tired, so I shut down the machine for the day.

The next day, I turned on my laptop to find myself in nearly the same situation as yesterday. It had to reboot twice for the firmware update exactly as described above, then the third time, it took me to my login screen, where I was able to log in with my new PIN. Now, this happens every time I start the machine and go to Windows 10 (reboots twice saying that it has to apply firmware update, then taking me to the login screen).

Current issues: The issues I have now are that Windows has to reboot twice or thrice to enter the login screen, and Windows Hello no longer works (I can’t even set up a new PIN!).

Actions taken to solve the problem: I did some research, but found nothing related to my issue. I ran the Windows Update troubleshooter and it found no problems.

Potential causes: I have two so far: (1) My dual-boot environment messing up the Windows 10 update, or (2) Windows 10 messing up its own update. I think my dual-boot setup has something to do with the issue because I have had a firmware update before, and it worked fine.

Specs of my laptop:

Name: Lenovo Ideapad Flex 5

OS: Dual-boot with Ubuntu 20.04 and Windows 10

RAM: 16 GB

Storage: 512 GB SSD storage

I’m not sure the specs will help much, but it doesn’t hurt.

P.S. If you need anything more, just ask.

Thanking you in advance.