Solution: I reviewed all the settings in IIS related to HTTP redirection and several settings reverted to the default Exch/IIS values while many settings remained intact from when I first setup Exchange 2013 OWA HTTP Redirection.
Here are the settings that I changed in order to make HTTP redirection work again, hopefully this can save you the work of re-doing all the settings:
– default website > uncheck ssl
– default website > check “redirect requests” checkbox, confirm /owa is entered and “only redirect requires to content in this directory” is checked
– Exchange Back End > check “redirect requests” checkbox, confirm /owa is entered and “only redirect requires to content in this directory” is checked
– Uncheck redirect on all virtual directories under Exchange Back End except Exchange and Exchweb which should stay checked. Public should and already had redirection unchecked.
– Uncheck Redirect on all virtual directories below Default Web Site
– Make sure Require SSL checked on all virtual directories under Default Web Site except Powershell which should be unchecked.
– Check Require SSL on Exchange Back End > owa virtual directory. It would be a good idea to take the extra time to confirm Require SSL is checked on all virtual directories (except Rpc and RpcWithCert).