Hello, I’m an advanced android developer and also very stuck in this topic,
Exported my sketch to Android Studio;
sketch = new Sketch();
fragment = new PFragment(sketch);
frame = findViewById(R.id.the_frame);
getSupportFragmentManager().beginTransaction()
.replace(R.id.the_frame, fragment)
.commit();
fragment2 = new ARHelperFragment();
frame2 = findViewById(R.id.the_frame2);
getSupportFragmentManager().beginTransaction()
.replace(R.id.the_frame2, fragment2)
.commit();
→ Everything displays correctly by itself. (Either one of the fragments run by itself.)
When PFragment is .replace/.add 'ed BEFORE CustomFragment, the custom fragment fails at onCreate.
When PFragment is .replace/.add 'ed AFTER CustomFragment, no errors occur but just the PFragment takes up the entire space.
(There is no error regarding either of the fragment), it’s an issue of PFrame’s “blocking”(?) other fragments. I have never seen any issue like this in my entire android development time 
Any help would be appreciated, thank you…