From what I have been reading so far, it is important that you do not use more than 20% VC in your medium mix.
So, how much VC did you use???
Did your plants get enough sun?

I probably used 10% at the very most... so not very much. I am always at a constant struggle with sunlight... I only have a north facing window, so it gets a fair amount of sun, but it's pretty indirect and diffused light.

I gotta tell you that IMHO, worm castings never cause any detrimental damage to plants. When food passes thru worms, any and all fungi, or diseases, or unwanted pathogens are eradicated. Totally.

Chuckiebtoo

I use worm castings to help prevent fungi and disease.. There is lots of research suggesting this is true. Last year I used lots around my apple tree, and it was the first year without black spots on the apples!

I believe the best use of castings is to top-dress, make teas, or use a handful in the planting hole. I do not mix in larger amounts into potting mixes. I find the casts too fine and slows water and air movement through the container. I have plenty and use it quite liberally mixed with soil in the garden.

Good luck, Pete