Hi,
You may be experiencing this on your setup because of how the Surface reacts to the keyboard. The services or software that should allow the connection between the two devices may be corrupted. It's best that you reinstall the keyboard driver in Device Manager to repair the problem. Refer to these steps:
- Open Device Manager (Windows key + X > Device Manager).
- Expand Keyboards.
- Right-click on the adapter of the problematic keyboard and choose Uninstall.
- Restart your Surface and reconnect the keyboard. The adapter we removed will automatically be reinstalled.
Let us know how it turns out.
Regards.