Email accounts can't log into EX2 Ultra cloud

Dear guys, My EX2 Ultra update into 5.05.111 firmware and complete the Index.

My email accounts could not see the folders into WD Cloud.

.

Any email that i’ve added for each user are not able to access.
Because i can delete users from Local users and can NOT delete from cloud users.

Are there any way to delete emails (maybe from some list) and add the same email back?