Ok, for seeing how different browsers behave I now also tested under Edge (Win64). Same as with Chrome, the Unicode symbols are first not shown (double diamond with question mark per symbol). Yet after an update of one of the items in a particular view, all of the Unicode symbols are shown in Edge. Interestingly, this does not happen with Chrome, here only the item that was updated shows the correct Unicode symbols.
Any specific suggestions for user-agent strings to test with Chrome and/or Edge to see if the behavior changes?