An app I ran on Android system before Lollipop (LG G2 phone) where the system font worked inside the app, no longer affects the application (LG G3) in Lollipop. As far as I know, all settings are the same but the font will not affect the app any longer. Is there a way to set default font for inside of the app? I just don't understand because it was working before I upgraded by default to Lollipop but now, the plain boring font is set by default inside apps and seemingly unchangeable. I have not been able to find any information regarding this issue anywhere. Is there a savant out there to help walk me through this process to change it?
From what you're saying, I pressume you're on a 'Nightly' or unstable version of a ROM, or if its an OTA update that took you to Lollipop, there's a bug somewhere. Keep calm and wait for fixes, or if you're impatient, then behold below:
By the way With the right search keywords, I found this called Fonter:
Instead of only being able to change your entire system's font, Fonter allows you to choose separate fonts for individual apps. And with a huge library of free fonts to choose from, you're bound to find the right look for every app on your phone. - Quote from here
I have in no way tried the Fonter, but I am sure it might be the solution to your problem, for the time being, until the actual issue is fixed
However, since you say that issue of yours wasn't there initially, I will suggest you fix the underlying problem, rather than go around with a 'hack', kinda.