Hi!
So I had been having the same issue since a while. In fact, funnily, on the same day in the morning, when I first made a watch face complication as shortcuts, the entire list appeared. Later that day, when I went to change it, it disappeared. Only Shortcuts app showed, and no list of my shortcuts.
After searching a lot on the web, came across this link -
https://discussions.apple.com/thread/254725707?sortBy=best - and the steps worked for me-
iPhone: Settings, iCloud, in Apps Using iCloud expand and find Shortcuts, disable it and enable it back after a few seconds.
Looks like it's an iCloud sync issue with shortcuts. The above fixed it for now. Along with this, one can also try restarting the watch, the phone, and / or unpairing and re-pairing the watch. But re-syncing iCloud should do the trick.
Hope this helps!
P. S. I can see all my shortcuts now, but why is each shortcut from the complication of a watch face asking me to tap 'Run' and not running directly when I tap on it? The 'Show when Run' option is disabled in iPhone shortcuts.