m0useanswered grow question a day ago https://420life.com/wp-content/uploads/2021/10/Marijuana-Leaf-Deficiency-Chart-scaled.jpg
This chat can be handy for troubleshooting some leaf issues.
I'm not seeing any issues with Ca in the plant, that user posts the same thing on every question.
Ca causes burnt rust spots on the leaves and Mg effects the whole plant not just new growth.
To me it looks like an issue with a micro "Mn,Fe,Zn" or maybe potassium. Could this be from a PH swing, lack of it overall or to much of something else in the medium blocking it uptake is the question.
A diary would help and what you are feeding them. Till that comes up IDK how much help you'll find. Overall they are looking nice and healthy other then this outline on the new growth.