This is a problem I have confirmed with GarageBand and Cubasis on iOS.
When Displays::Display::keyboardInsets is retrieved after the virtual keyboard is displayed while activated as an AUv3 plug-in, no value is set.
When I run it in standalone, I get keyboardInsets without any problem.
I checked with JUCE version 7.0.9. I also looked at the commit log of the latest code and found no related modifications, so I suspect that the problem occurs in the latest version as well.
I feel that it is difficult to get the values correctly due to AUv3 specifications, but I would like to have the text input in the plugin, so a solution would be very helpful.
Any advice would be appreciated!