***UPDATE***
I should have mentioned i do not have a surface. I encountered a similar issue in the past where the number pad would disappear after returning a line in excel and revert back to the standard keyboard layout. I would have to flip back to the number pad every time I drop to another excel cell. This fixed that issue and at the time it fixed it for surface users having the same problem.
I have applied the settings on my setup (non-Surface laptop) and the keyboard layout is back with a number pad.
Surface must have a unique setup when it comes to the touch keyboard.
Below is a screenshot of my setup showing the keyboard working. I do not know what is different about the touch keyboard implementation on surface over other tablet pcs.
Wondering if there is a set of files/settings that might be able to be ported over to surface to setup similar to my configuration where this works. If you find anything or need some system files to test out, let me know. I'll dig around but so far nothing.
I should also mention i've ran some scripts to customize various items. Its possible one of the tweaks has also aided in giving me this "working" setup. Script can be found here: https://github.com/farag2/Sophia-Script-for-Windows
READ and be cautious if you arent familiar, this can break your OS and you may need to do a fresh install.
Sharing my current version info if it helps:
Windows Version 10.0.22000 Build 22000
TapTip Version 10.0.22000.37
***UPDATE***
Shortly after posting this reply i noticed i was getting two separate touch keyboards. The stock versoin that does not have the numeric pad and the one that does after adding my registry tweak. Maybe the Surface is overlayed above the one that has the numeric pad and is not visible when you enter a text field. I added one more tweak to disable the keyboard from populating automatically. Less convenient but i now only get the one touch keyboard (the one i want). You'll have to tap the touch keyboard from the system tray to pull it up each time you want to type. Try this out and see if it gets you the old working version.
Create a new entry in the same location called EnableDesktopModeAutoInvoke and disable it with a value of 0.
***END UPDATE***