I suspected as much..
Issues such as this can often be down to blocked ports on your router. Firstly there is nothing inherently wrong with using your V6 via a non-VM supplied router & your SH in modem mode. I do it, and many other people do.
But.... "gremlin"-type issues with missing graphics, logos and suchlike, are usually caused by a blocked port somewhere. There would be concern if your OnDemand was flatly not working etc. You've not mentioned that, so I assume it's just a cosmetic issue?
The (potentially not so quick) way to prove this is to loop your router out of the equation, put the SH into router mode and connect directly. I appreciate it's not an ideal solution, but as a diagnostic/investigative step, is pretty surefire.
I'll pre-judge something else that many posters often query here. There is a "port configuration test" in one of the V6 menus that - on the surface - would help in situations like this. The test is (unfortunately, for cases such as yours) at best unreliable.
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