Don't panic.
Whilst the plant needs calcium, too much calcium can block the other elements. I used to have calcium problems because my water has no calcium at all. I only discovered this after I bought a cheap EC pen from Amazon, my water has a PPM of 23, which is stupid low. I spoke to my water company and their analysis of my local water described the calcium content of my water as nil. I give Calmag once when I pot them up. Once after flowering has begun and then every other week until a couple of weeks before harvest.
Biobizz are in the business of selling fertiliser products, they don't know or care how much calcium is already in your water, they just tell you to add it. If it causes a problem they can sell you another product to fix the problem. To me it looks like you leaves are starting to fade, which to me suggests a lack of nitrogen, which could be caused by too much calcium. I'd stop giving calmag and see if things improve.
Is this your first grow? I used to grow years ago and then stopped. I started again during covid. It has taken me a couple of years to get things dialled in, the learning curve is massive. Recently my regular brand of soil has been discontinued. I have basically started from scratch again. I was using a single bottle feed, in my new soil that wasn't working so well. So I went back to using Old Timers, very similar to BioBizz, I followed their schedule and immediately got nitrogen toxicity.