After remote started my computer auto shutdown in 15minutes how could I solve this problem

I wanted to have a family linux server and remote connecting it
A months ago I installed a hardware to remote start/stop/restart my computer, and replaced win10 with Manjaro 20.2 as my cloud server.
It worked good( all softwares) when I stayed home, then I went to work place(another city). then I found a serious problem: every time after I remote start my computer by the hardware it will auto stopped in 15minutes!
I already setted: settting – power – auto suspend --> close
besides,
after remote started I can remote login(ssh),and operate system before auto suspend;
if login into desktop with family’s help it doesn’t suspend

how could I solve this problem