collapsing mounds

A few of the soil mounds where I planted rhizomes have collapsed and the top of the rhizome is exposed. They have healthy leaves. Should I do anything about this?

The tops of bearded iris rhizomes prefer to be exposed.

You want them to be just a bit exposed in our climate, can you take a pic so I can see just how exposed they are? You may be OK.

It is fine, if you see roots put a little dirt around them.

It is not going to bloom this year (first year "Supreme Sultan"). Maybe when the leaves start to brown I should cut down the fans and mulch heavily? I'm worried it will dry up in our desert heat.

I was waiting for others to opine before putting in my 2 cents. In my area, 5b/6a, your iris
in question would be perfect. Some iris info sources say to cover the rhizome with about
an inch of fine soil when it would be subjected to extreme heat such as you would have in
Arizona. The rhizome can become sunburned or sunscalded by too much overhead sun.
In a normal bed where irises have a tendency to shade each other's rhizomes, the soil
may not be necessary. I would be happy to swap some of your sun for some of my rain.

you need a little more soil around the rhizomes or they will burn, DO NOT mulch, DO NOT cut the fans...when the leaves get brown you can pull them away from the base of the plant - if they are ready they will come, if they are too green they will not.....you have to do things just a little bit differently here -----

just a little soil.....don't bury them or they won't bloom....