I'm new to grow dairies but 10 plus years ago when I transitioned to growing indoors, Happy Frog was a goto. With a base of ocean forest when going from 3 gallon to 5 or 7 gallon for the 1st 3 weeks of flower.
Going from a Solo to a 5 gal is a huge jump. By going to a 5 gallon you've likley created a overwatering condition, meaning not enough oxygen at the roots when you feed or watered. This is most often the cause of weird deformed growth and you can have a new grower chasing all kinds of early stage deficiencies as well amdsome grow shops willing to sell you anything you think you need. Under development of roots and excess water is bad.
Try to not chase the deficiencies. Try not to react by throwing nutes at it.
Root cause at this stage is lack of oxygen at the roots.
This can throw all kinds of deficiencies that only require you let that soil dry out between waterings. Completely.
If you stay in the 5 gallon, expect a slow down or a complete stall in growth for weeks due to this. Likley weeks before the soil drys enough for roots to develop. Suggest you get a cheap moisture probe. Just for reference, not accuracy.
So you aren't tempted to water too soon.
Be patient, let the soil dry and the weed will correct itself in time if root rot doesn't set in.
Or,
If these were mine, I'd pull the the cup sized root ball out of the 5gal (save your soil) and put em into a 1 gal hard pot. Mix your happy frog with 20% perlite in advance before the transplant..
Trim all those huge hand sized leaves out. Definitely growing like a heavy indica. It'll grow leaves back fast in a smaller pot with more oxygen at the roots.
Water the 1gal until run off and leave for 1 week or until feels really light, water one more time and transplant 3 gallon around 3 days or when feels a little dry/light to lift. Then water just the outside rim of the next pot up. If the stem of a fan leaf points up it has enough water. Even if the leaf itself drops.
Dont stress how it looks today. Ive seen solid yellow clones grow pounds of healthy hard nugs after they were brought back to health.
All this growth your looking at is going to be old and trimmed off by the time you get to flower anyways. The damaged leaves won't heal. Trim off the sick.. Watch the new growth. Make her healthy for flower.
Don't bother reading the ppm of happy frog soil runoff. It'll be in the thousands when new. Its deceiving. Eventually the happy frog becomes imbalanced and required flush and a proper feeding schedule.
If your using any calmag, use at 20% . In happy frog, once your plants are taking off, you need almost nothing added to your water for a week per gallon of soil. Except calmag at 20-50% as your soil gets used up and your plant gets bigger.