Two Pi--holes here, updated both to 4.1 and started the chronometer display to enjoy the fixed display. One display was perfect, the other still had odd characters spoiling it.
Fiddling the terminal fonts had no effect but going back to the Menu, Preferences, Raspberry Pi Configuration then the Localization Tab and the Set Local button the good Pi was set to UTF-8 and the bad one wasn't. Quick change to UTF-8 and a reboot and now both Pi are pretty.