Okay, Troubleshooting update
Tried several different choices on changing the channel on the 5Ghz option.
Channels I tried:
Waiting up to 10 minutes after making the changes, booting up the Xbox One & the Blu-ray that are connected to the 880L & no DLNA share. The SMB share did appear within a minute.
Dug out the DIR-825 I have. While the Xbox & the Blu-Ray were connected via the 880L, 10 minutes on the stop watch, no DLNA share. For kicks I switched out the 880L with the 1522 & within a minute the DLNA share appeared.
As a completely off the wall try, in a VM on my PC I installed Plex & fired it up under normal setup (895L -> 1522) & the Plex DLNA share showed up. Removed the 1522 & hooked up the 880L, no Plex DLNA share.
I just don't think that as a bridge the 880L will show a DLNA share. For whatever reason it fails every single time.