TRUCK: 06' Ram 2500 (5.9); 284K miles.

BACKGROUND: Purchased truck JUN 2016 with 156k miles. Daily driver; mostly stock (minor mods).

May 2020: Purchased new injectors (50hp); FLUX DIESEL online (N.Texas)
Jun 2020: Added an 'extra' fuel filter; big screw-on type. Kept the original stock filter, so I basically have two fuel filters. GLACIER DIESEL
Dec 2021: Replaced all 6 fuel lines (nothing wrong with them, just had the time/money; figured it would be needed eventually). AUTOZONE
Nov 2022: #1 line cracked...sprayed the entire engine bay with diesel...unsat. AUTOZONE (warrantee'd)
Jun 2024: #6 cracked...while on the road @ night...it was a mess. Decided to buy a full set of new lines from GENO'S GARAGE (mainly because I wanted to have spares "just in case")
Jul 2024: Replaced the motor mounts (they were 'original' and I figured, maybe the engine was experiencing vibrations causing the lines to crack)
Feb 2025: #5 cracked on Feb 3rd (installed one of the spares from GENO's)
Feb 2025: #4 cracked on Feb 16th (installed one of the spares from GENO's)

DRIVING STYLE: I'm retired, 66yrs old. No racing or trying to prove myself to anyone. No 'chips' or computer mods. No hauling, other than maybe a riding lawn mower now an then. I change the oil and filter regularly (7k mil). Change fuel filters each oil change, along with air filter.
All the lines seem to crack at the nut nearest the engine block. All "tie-down" bolts are snug.

QUESTION: Why am I blowing fuel lines??