Definitely check your brix. If it's under 12, that's what you need to fix.
If you keep your soil on the damp side let it dry a bit. That promotes more oxygen, and lowers nitrogen synthesis. Both those things will increase brix, so if your soil is too wet, drying it is a two-fer.
You know calcium is good and I really doubt you have a phosphorus problem as your brix were high before, so over-watering/slow VPD, which can drop brix, is a likely cause.
High RH can too as it slows the plant, thus reducing photosynthesis, thus reducing sugar content.
So do a brix reading and if it's low, there are some good starting points to look at.
If you get brix back up you will get rid of them.