yellow spots have been showing up recently on two of my plants too (ima first time grower, indoor, soil)
i have read that it was because of too little nitrogen as well and just gave them some nutrients (12-6-6 to start em out, i heard when you start feeding 20-20-20 is ideal, but i wanted to start out smaller since they are only two weeks old and 7 inches tall)
ill let you know if the yellow spots go away in a few days (hopefully)

happy growing