Rust spots could be fungus but if you rub the spot with your finger and some doesn't come off innyour finger then it isnt rust spots. Magnesium or calcium shortage as well. Or lockout do to to much nutes or improper ph. Also can happen if you use cal/mg to often. Cheers
Probably is a lockout due to too much nutes. She had on one watering the wrong doses which could potentially be the problem. The rest of the plant looks great so I wont stress too much on it. Thanks for your msg 🤙🏾