It it because YouTube and WWE only offer 2.0 stereo audio and Prime Video, Netflix, and your cable service offers 5.1 multichannel audio?

Those apps worked last week with no problem so its maybe something with the system updates im assuming 

Are you using the YouTube and WWE apps on your TV or on an external media device?

I'm using them on my Amazon firetv and I have Amazon video and Disney on there as well and they work with no problem its those 2 apps that don't have the rear speakers working and they worked last week

Have you checked your audio settings on your Fire TV andTV to make sure nothing has changed?

Yes everything is the good on my settings the Disney and Amazon video apps work perfectly just the youtube and wwe network not working and the youtube app on my smart tv has the same problem