It’s oedema.

Oedema:

”Edema (oedema), a common physiological disorder, appears as bumps, blisters or crystal-like growth on the undersides of lower or older leaves on many types of greenhouse plants in the spring. Edema is not a disease like a bacterium or a virus, and it is not transmittable from one plant to another.” Tina Smith Greenhousemag

It happens when the soil stays moist for too long or when the plant absorbs water too much and or too quick. Not a huge deal, but those bumps will not go away. The leaves will eventually dry up over time. You will need to change the soil to a faster draining mix and the pot needs a hole if it doesn’t have one.

There is a drainage hole that I drilled into the bottom and it's in cactus/ succulent soil. I usually pull them out of the harsh summer sun around noon and just have them out early morning. Here is a better photo. It's just one or two leaves.

I'm having a hard time with the edema theory, I just checked the soil and its super dry all the way through hmm ( was last watered almost 2 weeks ago)

Use a chopstick to test for dryness.

There could be problem with soil staying wet for too long - even if dry now, about 2wks after watering. Is it possible that it was wet for about a week or even bit longer? When you checked, how did you to know it is dry "all the way thru"? As socks suggested, test soil with chopstick 3-4 days after watering.

For oedema to develop, it isn't necessary for plant to be in wet soil all the time.

Too wet for too long, I agree with Rina. Even though I have a very gritty mix, I watered mine too often and many leaves split like that!