If your test kits are reading correctly then if your alk is at 14 dKH and your daytime ph is only reaching 7.8 then there is something wrong.

Probably excess co2 in your tank or very often excess co2 in the room which is fairly common this time of year. Aerate some water outside and see if the ph rises and that will tell you if co2 is the problem.

There are some uncommon chemistry problems that can keep ph low when alkalinity is high. Very uncommon but since you say your calcium is off the charts then maybe???

Try the co2 test first and see if the ph rises.