E220 WOR Receiver wakes up only by ESP32 reset; not by external GPIO 15

[Tech500]

Using ESP32 Devkit v1, Ebyte E220-900T30D for Sender and Receiver. Have rung out wiring with DMM continuity tests.
Only have an AUX_PIN interrupt when receiver serial monitor is opened or ESP32 is reset; can see value of data after interrupt.

When opening a web request (10.0.0.27/relay); sender shows a successful web request; there is no receiver interrupt.

Able to produce receiver interrupt by producing receiver, AUX_PIN LOW.

Gist of code for Sender and Receiver