This is my 1st July here in Orlando and have a question about my AC
unit. It's a Traine Multi Stage Heat Pump. Never had cental air befor
only window units living in NY.

1st let me say I had the unit serviced a month ago and all came back ok
so this is just for my sanity.

Is this normal for a FL House with central air (I'm guessing so but
what to be sure):

House is 1700 sq ft cathedral ceilings, 8 ft on the low end 12 ft or so
in the middle. House is 60 ft long and 40 ft wide.
Sun beats on the roof all afternoon (Not the morning), no shade at all,
attic is like 140 degrees (Guessing not actual)!
Ductwork runs trough attic.
55% humidity or so at all time in the house.
78 degrees at the return, 62 degrees at the ceiling vents (I'm
guessing there is some heating from tracking through the attic as I
understand normal is closer to -20 degrees)).

So here is my question, I'll use Friday as an example.
92 degrees outside, with about 55% humidity, no clouds at all sun
beating on my roof, heat index of 104. House stayed at the set
temperature of 76 all morning until about 2PM when the temperature
began to rise to about 78 and never came down again until about 8PM. My
unit ran the whole time never shutting off till about 8pm. Is this
normal or could there be a problem? I'm guessing it's normal due
the Sun and excessive heat but just want to be sure.

TIA,
Felix