I have a similar issue. I am unable to sync to OneDrive personal (Office 365 Home plan) on my Android device (6.4.1.329). On my Windows 10 machine I also have the latest (6.4.0.632) but here I was able to sync (again). I don't have Onedrive for business, only personal.
Upon selecting "OneDrive" from the "restore from Cloud" list, it opens a link in my browser (at login.microsoftonline.com/...) but I immediately get the error message "Unable to restore data due to insufficient access rights". Even after Microsoft authenticates my login and redirects me back to Enpass, the error message persists. I tried the suggestion from @pallentx but it still does not work for me. As said by @RX7, the authentication from Microsoft is NOT received by Enpass app.
I was able to restore over "Wi-Fi" accessing the provided URL on my computer, but that's not ideal since the sync is not enabled. I then tried again to sync to OneDrive, but this time I get the error message "the sync with OneDrive was canceled by the user". Even after authentication on the browser, the error message in the app remains.
Therefore, since the latest version I am no longer able sync to OneDrive on my Android phone.
About the questions from @Garima Singh:
On which device and OS version(mention all) are you using Enpass?
Android version 9 PKQ1.180904.001 + Enpass version 6.4.1.329
Windows 10 version 1909 + Enpass version 6.4.0.632
How many vaults do you have in Enpass and which all cloud you are using to sync each vault?
One and synced to one OneDrive personal.
Which One-Drive account(personal, home, 365, business) are you using?
Office 365 Home plan
Try to open OneDrive in the browser and check how many folders of Enpass you have?
2, "enpass" and "enpass 1" folders. Only "enpass 1" is being updated when I sync from the desktop.
Any help will be appreciated.