Since I've upgraded to iOS 13, certain texts in some apps have the wrong font. TickTick is one of them. For instance, when you force press/long press on a reminder notification, the displayed font is a serif font instead of a sans-serif. It seems that Apple changed the name of the default system font and it falls back to the wrong font.

A quick Google search got me this possible related result: https://github.com/TextureGroup/Texture/issues/1701

Also, perhaps your team can check out this information from Apple: https://developer.apple.com/fonts/

Again, you're not the only app suffering from these changes. More developers are confronted with the issue. Check this Stackoverflow post: https://stackoverflow.com/questions/56470421/font-style-gets-changed-issue-in-xcode-11-beta/56470611#56470611

+1
Minor issue, but yes

Thanks for letting us know! We have been aware of it. The team will do further investigation asap.