Why US's F-22 Raptor, F-35 Lightning fighter jets can't talk to each other

Both the Raptor and Lightning II are known as "fifth-generation" aircraft because of their stealth, sensors and other capabilities

With the F-22 Raptor and the F-35 Lightning II, the US has fielded two of the world’s most sophisticated, maneuverable and stealthy fighter jets. They both function as airborne shepherds of America’s flock of older combat aircraft, using their state-of-the-art systems to communicate threats and targets on the ground and in the air.
 

Unfortunately, they have a difficult time communicating with each other.

The F-22, originally designed as an air superiority fighter, dates to the mid-1980s and was created to dispense near-invisible lethality against Soviet targets before the enemy knew it was there. The plane’s requirements for maximum stealth extended to