I concur with VE3FMC.
There was a special Russian event going on sending CQ that didn't follow the standard format. JT65-HF refused to cue it up for a response. I have seen others sending CQ DX <call> over and over and over .... only to die on the vine waiting for a reply, again JT65-HF refusing to cue it.
I would not detour from the standard format 'CQ <call> <grid>'
The fun of JT65 is waiting and watching for that unique DX call, then trying a QSO. It's a crap shoot, some days you see pole to pole and others your lucky to see the east coast of the USA (I'm on the west coast of the USA).
See you in the water fall.