I realize this topic is old, but not sure if it was ever resolved. I'm trying out one of these boards at the moment, this was the only topic I seen about the board and I encountered the same issues as above.

This is how I got it to communicate in the end and I thought I'd leave it here in case anyone else is looking at the same.

#define MY_RADIO_RFM95
#define MY_RFM95_RST_PIN 4
#define MY_RFM95_CS_PIN 8
#define MY_RFM95_IRQ_PIN 7
#define MY_RFM95_IRQ_NUM digitalPinToInterrupt(7)
#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR45SF128
#define MY_RFM95_FREQUENCY (RFM95_868MHZ)

Soft SPI isn't necessary, but the only issue in the code above was the missing digitalPinToInterrupt.
#define MY_RFM95_IRQ_NUM digitalPinToInterrupt(7)
I presume the following should work also:
#define MY_RFM95_IRQ_NUM digitalPinToInterrupt(MY_RFM95_IRQ_PIN)

@mrussi
Not sure if you still need this info, but I'll leave it here in case anyone else needs it. I couldn't find this either so i had to look at the heltec pinout diagram and compared to the ESP32 Library

/*
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2018 Sensnology AB
 * Full contributor list: https://github.com/mysensors/MySensors/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - tekka
 *
 * DESCRIPTION
 * The ESP32 gateway sends data received from sensors to the WiFi link.
 * The gateway also accepts input on ethernet interface, which is then sent out to the radio network.
 *
 * Make sure to fill in your ssid and WiFi password below.
 */

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enables and select radio type (if attached)
//#define MY_RADIO_RF24
//#define MY_RADIO_RFM69
#define MY_RADIO_RFM95
#define MY_DEBUG_VERBOSE_RFM95
#define MY_RFM95_RST_PIN 14
#define MY_RFM95_CS_PIN 18
#define MY_RFM95_IRQ_PIN 26
#define MY_RFM95_IRQ_NUM MY_RFM95_IRQ_PIN
#define MY_SOFT_SPI_MOSI_PIN 27
#define MY_SOFT_SPI_SCK_PIN 5
#define MY_RFM95_FREQUENCY (RFM95_868MHZ)
#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR45SF128

#define MY_GATEWAY_ESP32

#define MY_WIFI_SSID "WiFi_SSID"
#define MY_WIFI_PASSWORD "password"

// Set the hostname for the WiFi Client. This is the hostname
// it will pass to the DHCP server if not static.
#define MY_HOSTNAME "ESP32_GW_LoRa"

// Enable MY_IP_ADDRESS here if you want a static ip address (no DHCP)
//#define MY_IP_ADDRESS 192,168,1,100

// If using static ip you can define Gateway and Subnet address as well
//#define MY_IP_GATEWAY_ADDRESS 192,168,1,1
//#define MY_IP_SUBNET_ADDRESS 255,255,255,0

// The port to keep open on node server mode
#define MY_PORT 5003

// How many clients should be able to connect to this gateway (default 1)
#define MY_GATEWAY_MAX_CLIENTS 2

#include <MySensors.h>

void setup()
{
	// Setup locally attached sensors
}

void presentation()
{
	// Present locally attached sensors here
}

void loop()
{
	// Send locally attached sensors data here
}

@keithellis , I had similar issues with my setup although I didn't investigate it in any kind of detail like suggested above, my solution was simply changing the WiFi network. I was having intermittent connectivity issues with a number of ESP8266/ESP32 devices on my mixed 2.4Ghz/5Ghz Mesh network, so I switched back on my routers WiFi in 2.4ghz mode only and named its SSID "WiFi-IOT" and connected all of these ESP based IOT devices to it and I've had no dropouts since.

I have 4 MySensors gateways connected to Home Assistant, 2 by WiFi using an ESP8266 and an ESP32, the other 2 are Pi Zeros with 4G Hats connected by a VPN, since surprisingly I never had connectivity issues with the 2 remote devices and always the 2 WiFi ones literally next to the router I could only suspect the WiFi network. It may not be your issue but worth considering just the same. I think I will probably convert mine to serial gateways when I get the time.

@FlyingSaucrDude

What great timing (for me anyway), only this week I purchased the Adafruit RFM95 Bonnet version, and this thread is the only thing returned in a quick search. Your solution works for RFM95 also.

I didn't need to comment out the code that prevented toggling the CS_PIN, but I'm using the development version as the main branch dose not seem to build on Pi OS Bullseye.

./configure --my-transport=rfm95 --my-rfm95-frequency=868 --my-gateway=ethernet --my-port=5003 --my-rfm95-cs-pin=26 --my-rfm95-irq-pin=15 --extra-cxxflags="-DMY_RFM95_RST_PIN=22" --spi-spidev-device=/dev/spidev0.1 --spi-driver=SPIDEV

Thanks to your post I got this working in a few min of trying, would have taken me much longer otherwise, so thank you for posting to an ancient thread.