Ethelred, a partial workaround has been found... when the relay browser locks up, use the mini-browser to finish that fight. Further adventuring after that fight should be back to normal.
Interestingly, I get this happening ALWAYS on certain fights... mainly the various bosses. If I manually start the fight with The Man, the adventuring buttons in the relay window fight do nothing except grey the panel. If I refresh the window, I get the same lack of usefulness as is 'normal' for the relay. Switching to the mini-browser works, and relay overrides begin to show after the first action.