"Before I started my flight, I calibrated my compass"
Why ? Was it not calibrated already ?
"and waited till I got my home point recorded and my satellites."
Strange .. my P3S records Home Point as soon as I initiate Take Off. I don't get P-GPS unless enough Sats are locked in.
"So I take off and fly about 300m away and then all of a sudden aircraft disconnected on the app and I clicked rth on the app and it said connection timeout. Failsafe Rth did not kick in so I panicked and ran towards the location where my phantom got disconnected. Luckily, I got my drone to Reconnect and got my signal back so the first thing I did was click rth on dji go and it flew back. "
As long as you have default RTH set in your Apps programming ... which actually sets the aircraft failsafe action ... when it disconnected - the aircraft should have automatically started RTH. BUT ONLY IF IT WAS COMMAND 5.8GHZ SIGNAL disconnected.
If as I suspect - it was 2.4GHZ Video signal disconnected on your machine...quote"aircraft disconnected on the app" - then what you observed is what will happen - then the aircraft will not RTH as it waits for your next command. Trying to give command via Go will do nothing - the 2.4GHz link has disconnected but the 5.8GHz control link is still active.. You need to flick S2 switch to give Command signal to RTH.
Anyone I meet who is new to the Phantom ... I always show them S2 / S1 switch use ... its your lifeline to saving a Phantom ... your display is really a convenient tool but only additional to the real control which lies with the controller itself.
I also spend time with them to explain the difference of Control Disconnect 5.8Ghz and Video / Telemetry 2.4Ghz disconnect. To basically teach them not to panic and just revert to using S2 switch etc.
Nigel