That mix may be hot just by looking at your ingredients...Castings are hot af....I use
FFOF at 1/4 of my mix while the rest is inert...
Start by checking the pH of run off....My guess is its either to Hot and quite acidic and locking up.....(pH 5.5 or lower is not good)..
I'd check your pH first cause if the Plant can't uptake then its already done for....Humidity will help as well cause as the roots strike to your mix the plants will survive their transpiration...
If the Roots can't take to the soil then your stalled out and why your prob getting rot and shit growth...
But check ur pH, and make sure you dont over saturate your medium after transplant.,..are your pots feeling very heavy like their not dehydrating?....
Get a Plastic bag or some type of Humidity Dome on them if your sweating Humidity....
But theres a few mosre ideas for ya but dont over Love them or Over think it, ..ya just growing Plants atm...the tricky part is Flowering/Fruiting.....power to it
Spicoli/FOE20