Try cloning the 1 in trays with rock wool or root plugs and set on the floor. I went back to trays and rockwool just set it and check back in 2 weeks to up pot. I don't even put them under lights just on a table in the veg room lol.I have a strain that's a temp bish. 1 of 18 I run have this issue. Aside from just putting them on my cold basement floor last night, chilling the water is needed.
If I didn't like this strain, I would never even bother.