When I did mine I’m pretty sure I opened the bleed nipple more than 1/4 turn. It wouldn’t go in on 1/4 turn, as I didn’t bother with instructions I just opened it more till it went in. Probably best parts of a full turn IIRC.
as mentioned with the epic kit yes you have to remove the plunger from the reservoir end. You seem to have everything else cock on so if you can’t bleed them with the nipple open a good full turn sounds like you have an issue that’s more serious.
What about trying attaching the funnel to the top, filling that with fluid and then pulling through from the caliper end? Maybe something has broken off inside causing a blockage?