Problems with Feurwerk seedlings only

[gimmieToms]

Every year this happens with my feurwerk seedlings without fail. They never actually die, they always grow in to healthy plants after they are moved to the garden, but I’ve tried everything to stop this happening and have no luck. They grow leggy, pale, and the leaves ALWAYS curl.
I’ve included pictures of a couple of my other varieties so you can see I do actually know how to grow tomato seedlings lol. I’m pretty good at it I think. Just this variety does this.
I even left them in the smaller pots an extra week as was suggested by someone here to see if perhaps less root shock might help, but no.
Ever happened to anyone else? Any suggestions?
I’ve never had one die, they just look like they are dying until they go outside and grow for a few weeks. Then they are one of the healthiest ones I have. It’s so bizarre.