I read the sticky, but can't see how it can be a PH or deficiency or ... and only affect two of the plants.

Soil was mix of seedling starter and Supersoil. Water every 2-3 days. 24 hour light. Humidity is low and temp is warmer than optimum. Good air recirculation.

Pots are 5" (1 quart) and may need to be repotted soon, but if that was the problem, wouldn't the larger plants show root stress first?

Lights are 3 each 15 watt LED spotlights and 2 cool blue and 1 warm 26 watt CFLS. They are about 4-5" above the plants. Again, if it was light burn, the taller ones should exhibit stress first as I just raised the smaller ones.

The two larger are about 8" and the smaller ones are about 6" tall.

Can't do pics now, but may try later.