Using “japanese quotation characters” (not sure what they are called, but these 「」) breaks furigana for the next word.
「電気の町」秋葉原｛あきはばら｝
Removing the first part fixes it
秋葉原｛あきはばら｝
Adding spaces or other characters between the words doesn’t help.
This happens with Kitsun’s default layouts too, so I don’t think there’s anything wrong with my layout.
EDIT: It had nothing to with the quotations it seems (sorry for being hasty), but just the fact that there were kanji with no furigana attached. Changing the field to 「電気｛ ｝の町｛ ｝」秋葉原｛あきはばら｝fixed it, but I’ll leave this here in case it’s considered a bug and not a feature.