I would suggest a complete reinstall of Windows 10. I had the exact same issue – didn’t matter what I changed to English (UK), some things still didn’t work correctly.
Same here when loaded the finnish langue pack. Result was a mixture of finnish and english menus. After couple of reboots /sign ins it sorted itself out. The tablet was delivered with us english only.
For those wanting to change Windows from Chinese to full English (or other languages), do this:
Tap Start and Settings.
Tap Time & Language.
Change time zone to your time zone and tap Region & Language.
Change the region to your area, tap English (United States) and tap Set as Default. You can also remove Chinese to free up a notification area slot. Now tap Additional date, time, & regional settings.
Tap Change input methods. Remove Chinese. Tap back and then tap Change location.
Set location to your region. Tap the Formats tab.
Change Format to your desired language. Tap the Administrative tab and tap Cooy settings.
Check the two boxes at the bottom and hit OK. Then tap Change system locale.