We also received this error, resubmitting the app (with a new build number) worked.

Another tip is to plug the monitor and power into the right hand side ports. If you plug them into the left ports your machine will generate heat near some sensors on the left side, causing a kernel_task process with high usage to appear in your Activity Monitor. This is a throttle and can cause all kinds of weird issues. I’m having good luck with clamshell and external monitor now that I made this change. I’m running 10.15.5 on the base model 2019 16” MacBook Pro.

Are you asking how to market and list your app, or just how to distribute apps in general?

I've been rejected for all kinds of trivial stuff, mostly meta data related things. I know it's hard to hear, especially when its a 1.0. Just be patient, I expect you will have an answer by Tuesday. You know it has to be crazy over there in Cupertino with Corona/WWDC. Can you talk about the app? Are you doing anything that involves screen sharing to another platform that has a store? Anything that makes you think that it wouldn't get accepted?

Are you streaming video, or is it from your camera/local files?

The 2020 Stanford iOS courses were just released for free on Youtube. Stanford CS193p - Lecture 1: Course Logistics and Introduction to SwiftUI Professor Paul Hegarty is a legend and has been teaching this specific course for a decade. Hacking With Swift by Paul Hudson Ray Wenderlich Tutorials If you are just starting, I suggest you avoid all the betas. Stick with the stable version of Xcode and don't worry if you see a million buttons and settings. You will learn them over time. Find a mentor, be humble and remain enthusiastic. Welcome to the family!

My 1st gen SE on iOS 13 works on cellular. I’d do a full reset, if that doesn’t work it might just be a hardware issue, swing by an open Apple Store.