I'm glad you solved it!
That's what I saw on mine. I was able to right click and one of the options is eject (or unmount, can't remember exactly). Once I did that the boxes went away and it connected.
They came back up at each startup. I was able to disable it with a command line instruction, but can't remember which one. Let me know if the right click worse, if it does I'll find the command that disabled it permanently.
I had that on RPi3. When I remoted into it the camera had been auto mounted on the Pi. I was able to eject from there and it recognized the camera. This was a 1Dx, but may be worth a look.
The lens is a 100-400 f/4-5.6 II, great lens. I have a 500 f/4 I am going to to, but I wanted to make sure I had everything dialed in before using that one.
It's all working! Last night I took multiple sequences, lights and darks, all automated. Plate solving worked well, Guiding was good, and no issues with the camera. Now to work on fine tuning the settings (and processing), but first images are below. What a great tool!
Here's my current setup, out for it's maiden voyage. First picture included.
Skywatcher NEQ6-R Pro
Canon 1DX, assorted lenses
Astromania 60mm guide scope
ZWO ASI120mm-S guide camera
StellarMate running on Raspberry Pi 3B+, 3D printed enclosure
Thank you Herrhausen - that worked. Previously I had mirror lockup turned on and it was refusing to take the picture; I suspect I had it turned on in the camera and off in INDI. With both enabled it seems to be working.
For the "Saving Image", once I changed to save to SD it hasn't come back. I'm hopeful it's ready to go.
Update: Tonight I was successful running multiple sequences with the 1DX. The settings I used were below. If I changed one it would return to having 1 light image and 1 dark image, and the entire sequence were the same 2 images alternating (light, dark, light, dark). The Lights and the Darks both had the same 2 images. I think they were queued up in the camera but not saving, so it kept sending the first images it had. When I turned off the camera it was giving me a "Saving Images" graphic on the camera display that would not go away (which caused me to think about images getting caught in the buffer).
Settings that worked:
Mirror Lockup = 0 (It I set the mirror lockup on it would fail, and I would need to reboot the system and restart KStars on the Mac)
Force Bulb = OFF (Camera was set to Bulb mode, if I used Force Bulb it would fail)
Capture Format = RAW
Transfer Format - Native
Capture Target = SD Card (I think this one was the key in the Image Settings tab)
SD Image = Delete
I'm going to setup with the mount tomorrow evening and give it another go. There really isn't anything here that is a problem. I like mirror lockup, but on these long exposures I do not think it will make a difference.
I still suspect there could be something in the camera settings affecting this, but my bench trials this evening were working.
Thank you for the information. I've been having some issues, this will give me some things to try!