They are about 6 inches. I had them 6-7 years ago, they were subadults. All you say can be true, maybe it´s just impatience and with tortoises things need their time.
Anyway I will try to change some things that can be wrong. I have seen in this forum about low hibernating temp. I will use the fridge for cooler hibernation. I will also let aestivate the ones that bury, in case it helps.
Any new ideas or suggestions are welcome, thanks for the help.