Is this normal or a problem?

[Bud Lightyear]

Hey guys, any idea what this could be or if it's normal? I'm clueless. Thanks

[DW2]

Howdy Bud Lightyear, Look on the under side and see if there are any critters, it looks (to me) that something is dinning on Your plant.
Good luck with Your grow.

[rockman]

Howdy Bud, sort of reminds me of leaf miners chewing though inner layer of leaves. As DW said,any signs from underside of those tiny miners having entered the affected areas? Sometimes with miners you can spot the culprit as a small bulge, then you can do a little squeeze, which will put an end to that chewing.
Or this might be a nutritional deficiency, which maybe someone may have dealt with, and will have your answer. 🌿

[Bud Lightyear]

Dont really see anything there ...I will do a pH test maybe that will tell me more