Personally I think it was damage/stress from the cold winter. My Chindos here in zone 7a are no more. My Ilex latifolia has many leaves looking like your top photo.

Yeah Dave is right, cold damage causes cellular death which allows decay organisms to start growing. That's what you're seeing. Looks like the plants themselves will recover. Just let them be, no fertilizer, they don't need your "help".
There was a huge Chindo at the University of Delaware that was cut back to a thick trunk after the prior winter...now all the regrowth is dead. I wonder if it will manage one last recovery...

I wonder how the big ones in the Enid Haupt garden off the mall are doing.

what is not clear ... is if these are old leaves.. or the newly emerging leaves ...

i dont really treat old leaves .. the disease could be long gone.. as in.. it attacked last fall ...

transplant is also an incredible stress ... and stressed plants.. aka leaves.. get attacked ... by a multitude of problems ...

a pic of the whole.. would help us understand the problem a bit better ...

i also note.. you have planted a monoculture ...

ken

New leaves are just emerging on chindos this time of year. Those look like last year's leaves.

I am a scout at a nursery. The photos of the vib chindo show anthracnose,cercosopora, which are all fungal issues. You will see fungal on new leaf growth as the top picture shows. The second and 4th photo shows bacterial leaf spot and fungal. The bacterial spot are the brighter yellowish colors.

I have the exact same problem. My research indicates leaf spot fungus, so now I don’t know what to do. I’m also in NC and I did some hard pruning. I am now going to try homemade spray of baking soda. Here’s hoping.