My font settings are currently not being honored in quizzes. I saw a recent post from a couple weeks ago that said ublock origin could cause issues with this in the browser, but I am currently on the android app, so I hope a new post is warranted
There seems to have been an update to Android (or a version of Android - I've heard others with this issue on Samsung devices).
There might not be anything I can do about this. Basic is the only "font" choice in renshuu that does not actually have renshuu load a font - it provides the system with a list of suggested fonts, and the system chooses one of those in order. There is no way for me to know which one has been chosen.
All the other fonts are supplied and downloaded by renshuu.
So my suspicion is that recently, some update to the OS changed what fonts were available OR the way they were named, and that has caused renshuu's font suggestions to go unheeded.