I use Supernotes on an iPad with an external mouse and keyboard. I haven’t run into this issue with other apps, but on Supernotes most of the time I can’t scroll using my mouse scroll wheel. An trackpad actually works fine, it’s specifically a mouse that has the issue.
I found if I start scrolling on the iPad screen, I can keep scrolling using the mouse. But It won’t let me start scrolling using the mouse.
It’s tough to capture an example but let me know if something would be helpful.