Which Sonos devices do you have? What model router do you have?

I have a play 1, S1 and Ray. Standard Comcast router installed in 2023

Are any of your speakers close enough to your router to be wired with an ethernet cable?

I have the Xfinity XB8 Gareway.  Sonos things work pretty quickly here.  Not neck-breaking speed, but fast enough.

Not close enough to the router to use an ethernet cable.  Just wondering why the SONOS app is the only app that takes 90+ seconds to load.

Not sure. The app only takes about 3 seconds to load for me.

Does your WiFi network have separate 2.4 GHz and 5 GHz bands?

Yes, I am using 2.4 thanks to some security cameras.

Security cameras can put a lot of data on a channel, I had to move mine off my main WiFi to get it to work well, they were pushing channel utilization up to something like 65% by themselves and causing a lot of dropped packets.

If your router doesn’t give you that kind of information submitting a diagnostic and calling Sonos might get you a better idea of your situation.

Probably because other apps don’t have to reach out and identify your Sonos speakers before they start up, as the Sonos app does. 

OK, that might be the problem. If that’s the case, other users would have the same issue.

Only if they have similar network issues slowing down the app’s ability to reach the speakers, certainly. For those that don’t, the app would be significantly quicker to load. 

If you can't switch off the security cameras to test or see your Wi-Fi channel utilization then a diagnostic to Sonos and a support call are in order.