Hi, I have this problem. I attach a simple project in order that you can replicate this issue.
The simple project is in this link
Instructions:
Put in ad-hoc mode your Mac, create a network and launch in a shell server_udp.py
Launch socket-test project in a new iPad, for example A2230 (MY2V2TY/A) model with iOS 14.5.1 (or 14.6)
Run in another shell of the Mac ifconfig command and write the ip (something like 169.254. ...) on the Destination IP in the socket-test app in the iPad
Select an interface (for example en0), press Init and then Send. In the console of XCode, iPad prints that it sends 4 bytes, but nothing happens in the server_udp.py (in fact there is a print when it receives something).
If you try the same procedure with old iPad model or in AP mode, everything works fine!
I have also an update: after you follow all the instructions, try to do this:
disassociate Mac from ad-hoc network
riassociate from the list of airport (iPad continues to be in ad-hoc)
Select an interface, press Init and then Send. In the console of XCode, iPad prints that it sends 4 bytes, AND finally in the server_udp.py happens the magic.
Why if I create the ad-hoc network on my Mac first, iPad cannot send packets?
Thanks in advance