We recently switched our e-mail account from using IMAPS (for Inbound) & SMTP (for Outbound) to Exchange. We granted the app permissions and was working well. 

This morning we changed the password on the account and it stop processing inbox e-mails. We tried to remove & re-add, remove app permissions, re-add, etc... with no luck.

We also notice when the account is set, if we try to reply back to a ticket, we get an error of 'Error while processing the request! Ooops! Something went wrong. Try again later'. However we can confirm the e-mail does indeed send out from the mailbox and the recipient receives it. 

Any thoughts? I tried reaching to support but no luck yet.