SOLVED!!! Wow, this was one of the hardest problems I have ever had to solve.
The solution was to add all PlayerCameraManager classes to my Game Mode >> GetSeamlessTravelActorList thereby preserving them across the seamless server travel process.
Basically, if you are using a combination of multiplayer, seamless server travel, pawn cameras, and the “Set View Target with Blend” then it is critical that you do the above. If not, your “Set View Target with Blend” will stop working after one server travel.