Clones keep dying

I have a problem which seems to be getting a more regular occurance when taking clones use a reliable method, lower branches used, spray two days before to flush ,trim leaves etc etc place in propogator in rockwool pre soaked blah blah the problem is more often than not clones seem to wilt within six-twelve hours and the stem below surface of rockwool seems to shrivel badly is this ..because the temperature to high ,not cut underwater and airlocked ,disease ? I had a very good suceess rate on the first four or five sets without propogator 90% ish.. also seem to be taking long time to root into cubes upto six weeks with one variety

Used clonex rooting gel ,pure water and vitalink bio plus root enhancer

pls any help appreciated.. sorry no photos disposed of last attempt fear of disease cleaned prop..

I use soil for my clones with root powder. Make sure you don't have any big leaves on clone. It'll suck up all the energy. And don't over water during cloning, just always keep the soil damp. I get atleast 90% success rate on my clones. High humidity and a good fan helps.
They'll look like shit for about 2 weeks but then they'll start putting on new growth. Clones take paitience