What kind of issue do Mataro Blue have ?

Transplanting an already stressed plant isn't a good idea even tho I hardly notice a slow in growth, I guess trick of the trade after so long. No drainage is the biggest nono. Water pulls air into the soil when watered, with no drainage this can't happen and slowing killing your roots off because they can't breath so to speak... saturated, wet-dry cycle is life or death of a plant.. Good luck.

I have had a look at your diary too. Probably transplant and training has slowed her down a tad. Would have been better transplanting then waiting for her to establish herself in the new pot before any heavy training. She should be OK over the next week.

It takes times for plants to establish themselves in the new pots and till that happens the growth will be slowed a bit as its focusing on root development vs leaf. Its also why its staying wet for longer as the roots are not in that part of the pot yet to suck up all that moisture. Also good points made below about defoliation and topping. two stressors added onto transplanting and its gonna take some time to recover. If their are less leaves it does not have the same energy output as a plant with more leaves. I don't think you needed to strip the plants at all. they are small. Next time avoid this for faster growth. The markings on the leaves could be from Ca issues or just a bit of burn from over feeding. I would not do anything though and just let it recover. If it progresses then treat it. as it might find what its looking for in the new medium you transplanted it into.

Red it wrong. You transplanted 2 times in a week by your diary. This was hard on the plant. Stripping it down of foliage and topping was hard on the plant. It will take some time to recover from these events, at least 2 weeks before she starts to grow normal again. Give her time and have patience. It’s not good to strip a plant of all its leaves, it has nothing to carry out photosynthesis when you do.