You are saying the “Everywhere” button is missing from your Controller’s Grouping screens?

Un-Grouping is usually a symptom of network interference. I have no issues here grouping 10 Rooms and keeping them Grouped.

Before I wrote these posts, I did search the forums to confirm similar complaints.

> I have no issues

It is disappointing the best these forums can offer is gaslighting.

Since my rooms are different sizes the same output Volume in each room in the Group would be awful.

Wow, that is some attitude. This is a user forum and someone has offered some advice and that’s your response !.

At risk of getting the same…. Try rebooting your router and power cycling all your Sonos kit, as previous per response, you may have a network issue which is preventing Sonos seeing all your players. If this fails try the Sonos support line. 

> someone has offered some advice

There was no advice offered. There was an unproductive statement equivalent to “it works on my machine”.

“often fails. Speakers become ungrouped” is not “speakers became ungrouped one time”. Is the suggestion each time speakers become ungrouped, power cycle the system?

No.

Yet you do not answer the question “You are saying the “Everywhere” button is missing from your Controller’s Grouping screens?” that could be seen as good advice.

Normally speakers should only ungroup when restarting, in most cases an update (usually once a month). You could take a look at your network if Sonos devices u group more often.

Future readers - This is most likely an issue with Sonos software. See this is excellent write up on the flaws of the current Sonos software.

Still no answer on the Everywhere button.

I can see the “Everywhere” button and the groups I have created. That button existing does not address:
 

The experience for doing is is cumbersome and often fails. Speakers become ungrouped, alarms can’t be set for groups, and you can’t “cheat” and add all speakers to a single room.

It doesn’t address all of it, just the bit I’ve bolded above.

But since you are seeing it there is no need for it to be reported to Sonos an a bug that needs fixed.

You say the answers you have been given are gaslighting, you are welcome to feel that way but do understand the folks making them have found they help others.

You are describing the experience of many in terms of a regression in reliability of groups and overall user experience. I hope as Sonos continues to do firmware and app updates to address the mess their update caused we will see better reliability. 
But I wouldn’t hold my breath about the alarm improvements to include groups or even “everywhere” but just mo