Labels Disappeared on SPA504G After Adding SPA500DS

I originally started out with a bunch of Cisco SPA504G phones which were working normally and showed all labels as configured in EPM. However, when I added an SPA500DS sidecar to five of the phones, the labels on the SPA504G went blank, but their configured functions still worked. I duplicated the configuration profile for the standalone SPA504G when I created the profile that includes the SPA500DS and I have since verified that the two configurations are identical in every way. The other weird thing that happened is that the built-in web interface on the SPA504G is no longer accessible using the configured admin account, so I can’t access the web interface at all.

Has anyone seen anything like this before?