I understand that you’re seeing lag in the bootloader, and that is an issue that you should contact support about.
I’m not asking you to install fedora to your drive, just to check if a fresh distro on a live USB resolves any issues (this is a usual first step that support would ask you to test).
That said, since you are seeing issues in both Linux and Windows, it seems like the best option for you is to contact support and ask for more in-depth help. Its possible that you are experiencing hardware issue that just happened to show up when you updated, or a bad firmware update causing you extra trouble.