Describe the bug
There appears to be a regression in the test case:
Group - Deep nesting is possible (iOS only) - steps

To Reproduce
steps

Following those steps I have:

• Group 1
  • Paragraph
  • Paragraph
  • Image
  • Group 2
    • Paragraph
    • Group 3

Trying to add to group 3 pops the error here:

Smartphone (please complete the following information):

• Device: iPhone 11
• OS: iOS
• Version 13.5
• Found running against the Mono repo builds as well as develop tested at 053837669740bc7015587fe2d3bebf6547d5ef53 tested in WPiOS

Additional context
I'm not experiencing this issue in WPiOS 15.1