Q.winter protection of plants
This year I used green fleece in my echium pininata. However, I have just discovered those covered have dropped most of their leaves when those not covered and growing well. I never had this trouble with white fleece. Your comments please.

Though these products can certainly offer protection, there is danger of excess heat and moisture building up; even on cold days.
Wait and see, and I suspect your plants will recover.
https://www.gardeningknowhow.com/plant-problems/environmental/plant-covering-materials.htm