Question how to rollback BIOS version Ideapad 320 from 4WCN47WW when the previous version is not available on the website


May 26, 2019
So recently my laptop keyboard stopped working suddenly and only the power key and trackpad was working. I tried everything related to driver update and windows update but nothing seemed to work. Then I updated BIOS and it started working again.
Now the problem is back again and this time when I go to update the driver it gives Code 10: This device can not start. and when I tried to update the BIOS it says that it is already on the latest version. So I'm thinking to roll back the BIOS version to 4WCN46WW but on the website, it is only showing the latest version 4WCN47WW. The BIOS startup time has also gone up to 65 seconds. If there's any other method also please help

320-15IKB (Type 80XL, 80YE) Laptop (ideapad) - Type 80XL
Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz 2.71 GHz
8.00 GB (7.88 GB usable)
64-bit operating system, x64-based processor
Windows 10 Pro
Version :21H1
OS Build 19043.1165