If you are facing problems with updating the webview, you can try to enable dev version of webview (it will be newest version)
you can watch this video to enable dev version of webview
Basically, download dev or canary version of webview from the Play Store, and then enable it in the developer webview settings.
If nothing works, try to update your Android Operating System to the latest version if possible.
if you are still facing graphical or crash issues, please contact me at
ching.huang.dexter@gmail.com.
I will try my best to help you personally.