I was just flying from TNCM to TNCS and I was told “frequency change approved”, no handoff. Then when I left tower’s frequency I was immediatly sent a on guard message from approach. There was no departure frequency avalible when I left tower’s frequency.
I know that I am not supposed to contact approach when I am a departure and told “frequency changed”. I also know that sometimes approach will handle both arrivals and departures. I can’t read minds though so what am I supposed to do next time and is this my fault. Trying very hard not to get ghosted.