Shame this did not get resolved, I experienced this last night in a dark sky location. I did manage to fluff around with the timing of the camera with the Ekos operation, but can't remember how I did it. Now that I am home the same is occurring.
I noticed that the camera is doing un-usual things not normally. The red light flickers when switching on, the display goes busy than normal camera operations. Finally, after locating the error, I came back to the camera, switch it off and the "sensor clean" display does not appear as usual.
This was with the Canon DSLR Driver, I tried to use gphoto, but the error message appeared.
I will try and fluff around to get it working unless I find another post with more details.
Last night INDI version was 1.93, today it is 1.94. So it is an ongoing issue but never seen it before.