Yellowing and Extended Claw

Hey folks, got a problem with a plant that I decided to put in my 3x3 solo and attempt a first scrog with.

• Full Moon Fever (GreenPoint) plant in question is a clone from the same mother plant I still have. Have been very successful over the past year and a half with this strain & particular phenotype for personal grows.
• I use a 4VS Timber light.
• Coast of Maine Platinum soil from beginning.
• plain Ph'd water.
• Transplanted from 2 gallon fabric smart pot to 10 gallon fabric smart pot approximately 4 weeks ago. Needed that amount of time for the plant to train outwards on the trellis string prior to flowering.

Issue:

• Over the past month the weather up here in VT has obviously changed. I use a heat mat under the plant with the probe down through the soil about 1/2 - 3/4 the way down into the soil to monitor root temp. Temperature on temp controller for heat mat is set for 75F. This works very well during the winter months me as the room itself is insulated but not heated and can be kept anywhere from 62-72F. I have been successful with this set up for plants going into flower during this time of year and have never had a problem.
• 2 weeks ago I fed with biocanna (BioVega) thinking to give a bit more of a boost before flipping as I planned on flipping to 12/12 this week. Well that sounded good at the time anyway. I only mixed this at about 1/3 of what they called for though, with ph'd water.
• each watering since the biocanna feed has been solely ph'd water.
• This week I started to notice that none of the leaves were fanned out anymore and all curled under in the claw position and the leaves have significantly turned more of a yellow green than the nice green that ya want from the week prior.
• I watered 2 days ago and with enough for some passing through to drainage, I would not say a full blown flush however.

I'm at a loss here as to what happened to this plant. The other plants in a different tent had the same feeding, same schedule, everything but they are healthy and not showing this problem like this full moon fever plant.

What could my issue be. What grower error may be the cause. Is there any saving this plant or should I scrap it and pull a different plant into this this tent to flower?

Thanks much for thoughts

They look underfed or there’s a nutrient lockout going on from salt build up in the soil, ph issues, or overwatering. Usually when the foliage is light and stems are dark it’s underfed and has been for awhile. I’d give em a good feeding with bloom nutes and cal mag. Maybe a foliar feeding