@sod Thank you for the detailed reply. I am also running iOS 16.1.1.
I just tried the Shortcut that does not use Humboldt. First I checked the Privacy section as you suggest. All permissions are allowed and relevant apps are accessible.
I uploaded a photo. It appeared to work fine. When I went to look at the image under uploads in the official Micro.blog app (not the current beta version), I saw as met with a grey square. When I tapped on it the image opened.
When I went to Upload in the web version of Micro.blog, where the image was meant to be, there was a “?”. I pressed on that and nothing opened and there was no HTML to copy.
The Humboldt Shortcut stopped short saying that there was a problem running the Shortcut.
I am about to go out, but will take another look later.
cc @pratik