I was able to solve the issue and added my work Gmail (google workspace gsuite) onto my P40 Pro phone successfully. In a summary, I think it may be because of the Google device registration but I am not 100% sure. I will explain the steps I did.
After several attempts of resetting up through Googlefier, I can't get my work Gmail to work so I tried out HuaGu app approach
www.youtube.com/watch?v=7kGkLsf83Bk Do steps 1 to 9 (while adding my personal Gmail & work Gmail on step 6 after microg is installed). After step 9, the phones will still show a lot of google-related errors, but this time, it actually shows the phone is not Google Play Certified error on the play store which is what I didn't have before. Move on to step 10 on the HuaGu app to sort out "play certificate protection" issue.
It actually involves installing an app called "Device ID" to get the Device ID of your phone and register it on Google (here's a separate tutorial about that part -
). After registering the Device ID on
https://www.google.com/android/uncertified, proceed with clearing cache and data on a few google apps as instructed by the HuaGu app, you will also need to restart at one point according to the instruction. After all the steps are done, my work Gmail account is fully working. All Gmail, contact, calendar, docs, sheets, drive, etc are working for the work account too.
Therefore, maybe it is the registration of Device ID, or maybe HuaGu app installed some services that Googlefier doesn't? I'm not sure exactly, maybe
@badmania98 or
@bender_007 can give some insight.
Hope this helps those who are facing the same issue as me!