I have both the pink and red varieties of Turk's Cap.

My red is scattered in both sunny and shady spots and it draws hummingbirds and butterflies in both settings. My pink is in a shady garden at the back of the house. It has drawn a few butter flies in the 4 years we have lived here. But it doesn't seem to draw them anymore. And to my surprise I have never EVER seen a hummer go to this plant. I know hummers will go to peach and pink flowers, as they get on my bougies that hang out front all the time. Perhaps they just haven't found it yet? They fly off across the area between my driveway and my neighbor's driveway a lot when they leave my red plants, and this little garden is right behind and beside those driveways, so I would be surprised if they haven't seen it yet. Any thoughts? Too shady back there for hummers to frequent them?

A shot showing fruit after blooming done:

The hummers use my Turk's Cap. I bet they are using yours and you just haven't caught them doing so.

Your plants don't look that tall? I can't really judge by your photos how tall they are. My hummers do like it when the plants are bigger, not so low to the ground. It's safer for them to be high off the ground in case a cat or some other predator is around.

My red plants out front are shooting up to 4' or more currently. The pink ones in the photo were shot last year. Currently they are about 3' tall (that cement curved wall is 13" tall), probably because they are almost in full shade. But they bloom a lot despite that shady setting. The hummers just aren't finding this planting.