I am using the iOS version of the MIT App Inventor Companion App and I am having issues with custom fonts I've uploaded to my application not displaying.
I have tried to check if whether or not this issue is mimicked on the Android version of the companion app, though there were no issues as the custom font displayed just fine there.
I am only manipulating the fonts through the design tab manually, using the "Upload File" option in the "FontTypeface" section of the Properties tab of the app Inventor.