@cj_c I have a work around.
If on filling in the account details and pressing <next> Dekko returns to the same screen do not back out as this deletes the new account information entered. Instead restart the phone.
If you entered the information correctly then your mail will be there when go back into Dekko. If the account details were not correct, you have the opportunity to edit the account.
Similarly if the validation hangs, simply restart the phone.
The lack of feedback from Dekko when configuring an account has already been raised as an issue.