Another update here.
As I stated, after a bit of trial and error, I got atmos working in tidal from my fire cube. But what is so frustrating to me, is that when I was having problems, I got misinformation and completely wrong answers from 2 support sources!
I had a very long chat with amazon support. That guy was completely clueless - kept copying and pasting anything he could find with the word atmos in it, to try and convince me that there was nothing wrong, I was just trying to do unsupported things - just wanted me to go away basically. He kept arguing that netflix doesn't support atmos, so no apps do, even though I was talking about tidal, and it specifically supports atmos. Unfortunately, this chat was before I found that tidal's page specifically states fire cubes support it. At some point, the amazon support guy insisted the only thing he could find that would support atmos on a fire cube is streaming Tom Clancy's Jack Ryan using amazon prime. I streamed that - no atmos, only dolby digital. He then said, oh, it only supports 5.1.2 or 7.1.2 - you said you have 5.1.4, right? I tried to explain that's not how atmos work - it will adapt to whatever speaker setup you use. He actually got a bit rude with me - telling me it's my fault that I won't configure my speakers properly. I humored him, set it to 5.1.2, and, surprise surprise, still no atmos. He escalated the case at that point - still no reply.
Meanwhile, when I found tidal's page specifically states a fire cube is supported for atmos, I figured, lets ask them. I submitted a ticket with all the details.
While waiting for a reply, I played around more - found information about uninstalling/reinstalling the app, disconnecting reconnecting the hdmi, and that tidal is problematic at recognizing and holding the settings anyways. Eventually what I found is, although my receiver was set to dolby, and automatically went into dolby digital or dolby digital + mode for the fire cube depending on what it was setting - it wasn't automatically going into atmos mode. But when I manually changed the surround mode to the dolby mode that supports atmos, bam, tidal sent atmos signal, receiver received it, and it works great.
Then I got a response from Tidal's support telling me the problem is that my receiver doesn't support atmos.
Really?
What a shame - atmos is doomed. I mean, the process is basically this:
Research different speaker configurations and buy a bunch of expensive equipment after research - I get that multiple layouts means versitility - but you look at the documentation showing the various speaker configurations, and damn, that's gotta be overwhelming. Maybe they'll sell a bunch of atmos speaker bars. But, I don't care what you send to it.....a speaker bar is a speaker bar, atmos or no atmos - you ain't getting anything I'd ever consider surround from a speaker bar.
Spend a bunch of money on a receiver and speakers - run wire everywhere - make holes - mount speakers.
Once everything is setup - figure out how to properly configure equipment.
blu ray players need to be in the correct mode to bitstream the dolby atmos signal.
streaming boxes need to be in the right audio mode.
The receiver might not automatically detect it's an atmos signal and put itself in atmos mode, you have to set that manually.
Using a PS4 as a blu ray player? Sure....you set the audio settings in the main menu to dolby bitstream mode - but there's a whole separate settings menu by pressing the options button while playing a blu ray - you have to set the audio to bitstream from there. What do you mean you didn't think to look for more audio settings after setting the audio settings in the main setting menu?
Then, if you can't figure all that out - you go to support - mind you, support for equipment and service you paid a bunch of money for - and you get misinformation and wrong answers from clueless workers that haven't been trained at all on these technologies, and have no reliable resources to turn to to get you a correct answer.
Meanwhile - my Yello bluray was out for delivery - listened for the doorbell all day - no doorbell. Stupid mail man left a slip in the mailbox that since a signature is required and "no one was here to sign for it", I have to pick it up tomorrow. Arrggh....I fucking hate our mailman, he pulls this shit all the time. There is always someone home. We have a doorbell. Yet, he'd rather be lazy and drop a slip of paper in the mailbox and lie that no one is home, then actually walk up 3 steps to push a button.
Good help is so hard to find. Unfortunately the future is rather bleak for Atmos.