Good morning,
Yes, it is a calcium deficiency.
What type of water do you use for watering?
Because I would say that you also have a chlorine problem...
To be continued
It appears to be calcium deficiency as you were thinking. Woukd apply some cal mag in next feeding. Would also test ph of soil. Always good to know what goes in and comes out of your plants to avoid issues or catch them early. Good luck and happy growing 🌱