hdmi monitor not working if u connect after armbian start

[ari1234]

i have orange pi pc plus board with armmbian installed on it, also im using X11 gui on it.

 

if i first turn on the monitor and connect to hdmi port and then start(power on) the orange pi  everything is ok .

 

BUT if i turn on (start) orange pi and after few minutes put the hdmi cable from monitor to it  then it will show nothig on monitor

 

so it cant detect monitor if i connect after armbian start.

 

how can i fix this