Black eyed susan vine advise

I am having trouble starting my Blk. Eyed Sus. Vine this year. I WS and have 1 tiny seedling. 1. Do you think it's because we've had too much cold weather?
2. I would think if one seedling sprouted, the rest are not going to?.
3. Should this seed be nicked?
4. Should this seed be soaked?
It's a big seed so I am wondering if it should have some sort of "treatment" before sowing.
Any advise would be appreciated. Temps to germinate should be 72*. We have some really warm days mixed with really cold days.
I haven't had trouble WS this vine in the past. I don't remember doing anything special to it.

patience, our weather has been cooler than normal this year.

I have 36 cells planted ,20 of them are 6inches tall,the others are in varius stages,I just saw 1 that is just germinating ,mine are under lights.did notice the seed case is not wanting to come off a few of them .Very hard seed case could be, not helping .Id bet they will pop soon

The ones I have under lights have sprouted. The WS ones are still doing nothing. It's 82* today. All my WS seeds should be popping today!

Soon Im sure = ) 82 lucky you...its suppose to get to 70s today an sunday,then back to 50monday...we have had a very cold spring ,still having..acckkk

Actully, it's pretty dog gone hot here yesterday and today. Low 70's is perfect and we have had almost none of that. We've got quite a bit of humidity and that makes it quite sticky. I brought my B. I Susan vines outside today in the shade.