Ok . some development... but not much progress...
Still unable to exit _handleRequest function. I tried to put while(1) loop to be able to go the further as possible and have the time to serial print a stamp... it is bugging there...
It is even more strange, it bug on "ionic cordova run android", and on real device... but it run ok ok ionic serve (emulator)...
I cant tel if the bug come for the ionic side or the arduino side... but it make the ardiuno froze so...
wish anyone have an idea what to tried...