I just looked up pairing F4251 and I don’t know what you were looking at but you were way off.

FLL to GYE to FLL: Block 9:10 / Credit 13:30....layover 23:50
TAFB: 35:30

Block:9:10
Duty Rig: 11:40/2 = 5:20
Trip Rig: 35:30 /3.5 = 10:08
Duty Period= 2 = 10 hours will fall short of 24 hour layover after PBS.

So: 10:08 plus 8% override actually you get 10:57 total credit