I understand that you're concerned for your plants. However, several of the photos appear to be sideways and/or duplicate the others.
Is it possible to take close-ups of branches/leaves where the disease/dying process is taking place? For instance, if the bark is flaking off more in one area than another, a close-up of the flaking-off bark would help.
Also, take a look at the wood beneath any loose bark. Are there pinpoint holes in it? Is there sap coming out from crotches in the branches? If so, take a close-up of one of those locations.
We may not be able to diagnose, but these kinds of photos will improve the odds of it.
Sunset Zone 17, USDA Zone 9