Okay, well, I don't consider myself a greenthumb but I've got 2 decades experience of popping seeds and have zero issues doing so.
So, you're getting tails in the germ stage in paper towels yeah?
But they stall out once planted?
I germ at 28c.
I plant in moist medium that I try to keep at 28c also.
Once they're above ground I try to lower temps to 25-26c and I mist them with plain water every few hours.
Try to keep humidity as high as you can. Wet sponges/towels hanging is cheap way but not all that effective compared to a proper humidifier. I'm building one now based the one
@OzyM8 posted. I had used pond misters before but never built a fan forced system which I suspect is going to make all the diff in the world in terms of efficiency. He will probably post that again for ya when he reads this cause he's a swell bloke.
All this takes place under just T5 fluros and they don't get moved to proper veg light for a couple weeks.