You can only have one Sonos account for the system, but you can add multiple accounts for the same streaming service:

https://support.sonos.com/s/article/3624?language=en_US

In addition to the comments from @ClausN , there is no such profile as a Sonos Admin.  Anyone with authorised access to your Wi-Fi can control your Sonos system.

I understand we can add multiple music streaming users. The issue is when we are both streaming it cuts off users EVEN when we are using our own separate streaming music profiles. (Example Spotify. We have two separate accounts on Spotify and using our own Spotify profiles, music still cuts off).

We had logged into Sonos using two separate admin accounts before. We moved and now cannot add a second profile to Sonos.

Hi. You have never had two Sonos accounts on a single system because that is and has always been impossible. 

If music is cutting out it has nothing to do with Sonos accounts.

Does your problem still persist? There was some trouble with Spotify earlier this week.

Spotify only allows one stream per Sonos system if initiated via Voice.  You can use the App to initiate multiple streams without issue.