@huey-le you could eventually give a try to :

hdmi_cvt=1280 720 60 3 0 0 0 hdmi_mode=2 hdmi_group=87

reference : https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=24679&sid=4c0e33c3e707fccba5494107fe8260a2#p227301