If it鈥檚 also supposed to be scrollable on iPhone, that too seems to be broken in iOS 13.
Can reproduce on iOS13 Dev. Build 2 on an iPhone 6s
Can reproduce on iOS13 Dev. Build 3 on an iPad Pro 10.5-inch
Can reproduce on iOS Dev Build 3. iPhone XR
Can reproduce. iOS 13 Public beta 2, iPhone 8 Plus
It turns out to fix this I essentially have to either reimplement scrolling from first principles or reimplement text selection from first principles. I don't have time to deal with this, so any help would be appreciated.
FYI - there is a workaround, I confirmed on iPad and iPhone (iOS/iPadOS 13 beta 4), you can scroll using an invisible scroll bar located roughly here:

Props to maskeda on discord for discovering.
cannot even use it on iphone xr 13.0 (17A5572a)
just white screen
will try to reinstal
nevermind it works now and scrolling is broken like said in the issue
Got this working on master.
Most helpful comment
FYI - there is a workaround, I confirmed on iPad and iPhone (iOS/iPadOS 13 beta 4), you can scroll using an invisible scroll bar located roughly here:
Props to maskeda on discord for discovering.