GG4 Autoflower with yellow spots on leaves 3rd to 4th week of flower

I have been growing two SSH photo’s and 1 GG4 Auto in a 3x3 tent. I have ventilation and carbon filter. The temp is 70-76* F, Humity is 55-60%. Was hoping someone would be able to provide some insite on what these yellow spots were that have been forming on the leaves, They go all the way through to the underside on the larger spots.

Any help would be greatly appriciated,

Thank You,

It looks like one leave just pull it ck for critters if no critters carryon.
Rest look ok as the stems turn red its usually old growth ok to remove so nutrients go to thriving flowers.
Welcome hope this helps

Thank You, for the reply It is actually on quite a few of the leaves. No critters seen, have looked
closely. New growth seems to be okay.

Could be calcium def. mobile nutrient so would notice spots on lower leaves first, which is supported by your comment on new growth being ok. Curious what others think as I’m honing my troubleshooting skillz

Using any calmag or oyster shell?