ADB wireless debugging port changes every time Wireless Debugging is toggled on the phone. After the phone screen locks or Wireless Debugging times out, the previous debug port becomes unreachable (Connection refused). You must re-pair AND get the new debug address port — both change.
When ADB wireless connection drops: (1) Re-open Wireless Debugging on the phone (it may have timed out), (2) Tap 'Pair device with pairing code' to get the NEW pairing port + code, (3) Run adb pair <ip>:<new-pairing-port> <code>, (4) Note the NEW debug address port shown on the Wireless Debugging screen (different from the pairing port and different from last time), (5) Run adb connect <ip>:<new-debug-port>. The pairing persists across port changes but the connect target must use the current debug port.