I'm running PlatformIO with Visual Studio Code, but I'm having the same issues on ArduinoIDE. To be clear, what I'm really looking for is an answer to "What do esp_now_send's return values mean" and not really looking to debug my code, which I'll gladly do myself once I can figure out what it's telling me. Thanks!
FWIF, my includes are as follows:
#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <espnow.h>
#include <stdbool.h>