We do not see indications of a fungal or pest issue on the pictured foliage. It does resemble cold damage and/or sunscald. Were the transplants acclimated to outdoor conditions for 1-2 weeks prior to planting them outside? If not, the shock of the change in conditions was the factor behind leaf damage. (Indoor window light or grow lights are nowhere near as intense as sunlight outside, and leaf tissue cannot adapt quickly to an increase in light intensity.) If the plants were acclimated, perhaps a chilly night (which have still been popping up in recent days) caused leaf damage. This should not affect long-term growth and the plants should gradually grow out of the damage. (Leaves cannot heal, but new growth should emerge normally after this cooler period passes.)

Miri