Everytime I hit Shift+Alt or Shift+Ctrl (Windows Keybinds for switching languages) it changes the input language without even notifying me.
You could also disable the keybinds/ keyboard shortcuts/ hotkeys.
Go to Settings > Language (tab on left) > Keyboard (one of the big buttons near the top of the page) > Input language hot keys (under Switching Input Methods). This opens the Text Services and Input Languages settings box (maybe you can search for that directly; didn't work for me). Under the Advanced Key Settings tab, click on the first listed Action, hit the Change Key Sequence button, and set it to "(None)". Do this for each listed Action and click on OK.
The keyboard shortcuts annoying you should now cease to function.
To remove unexpected languages, you could manually delete them from win10 Setting "Edit language and keyboard settings"
2.After the remove option appeared, click remove. As a result, the relevant keyboard will be deleted as well.
But if this is not the case, you could check if the suggestion of modifying registry key would help. https://answers.microsoft.com/en-us/windows/forum/windows_10-start/cant-remove-a-keyboard-layout-in-windows-10/058acf33-16d9-47f4-a24b-245b8823d90e?auth=1