First NEVER use shortest distance. NEVER.
check the avoid routes... you may have a setting wrong.
other wise do a Full Reset...
Many . I mean Many use the Rv760 for years with little trouble.
I have the 2597 and the Truck 770LMTHD..
Garmin discontinued the RV 760 some months ago... and NOW are about to release the NEW RV770. so its a good product.
all else.. contact Garmin Customer Service..
maybe you have a defective one... or some program ERRORS..
as for owners using a smart phone or tablet... you must never come to south Texas.. ATT & Verizon does NOT have good coverage here.