Check Under iOS Privacy Settings.
See if you can find the ASIAIR app under Location Services and Local Network in the iOS Privacy settings. You need to enable both.
I use three different ASIAIR (one version 1 ASIAIR as an All Sky Camera -- watching the rain pouring down in Portland at the moment) with three different iPad Pros and even an iPod Touch, and have yet to encounter a problem.
You can also try uninstalling ASIAIR (i.e., remove it completely from your iPad first, then reboot the iPad (General Settings > Shut Down), and after restarting the iPad and when installing again from the App Store, and prompted, be sure to give it permission to access navigation services, and give the app full network access.
I just tried turning off Local Network permission in iOS Privacy Settings -- the app will launch but will not find any ASIAIR hardware when Scanned.
There is a nuance in that an iPad since 2019 actually runs iPadOS, while the iPhone runs iOS. You might be seeing security differences.
Chen