Hi Ash, good morning! Thank you for the additional details and the screenshots.
Since the issue began right after your laptop was returned from service, and you're seeing the same erratic behavior even in the BIOS and with the On-Screen Keyboard, it does seem likely this may be a hardware issue introduced during the repair. Although there’s no visible physical damage, something internal might have been affected.
To rule out any remaining software conflicts or driver issues, here’s a link to some additional troubleshooting steps from Greg, another Independent Advisor: https://answers.microsoft.com/en-us/windows/for...
If these steps don’t resolve it, I’d suggest reaching out to the repair service to report the issue, as it could be linked to the recent repair. Please keep me updated on how it goes!