My guess is Xcode 11.4 does not support iOS devices introduced after Xcode 11.4's release, which was March 24, 2020. The iPad Mini 6 came out in 2021. Do you have another iOS device introduced after March 2020 to test my guess?
You most likely need to update to a newer Xcode version to install your app on the iPad Mini 6.
Topic:
Developer Tools & Services
SubTopic:
Xcode
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