In the watch editor, when selecting Tap Action for any element, there is an option "Watch: Select Application", which normally shows the complete list of all installed apps on the watch.
The list is identical to those, which is shown on watch. Sorted by application name.
On my Polar M600 it works correctly until I install "Bubble Cloud Widgets", which actually adds two items to the apps list: "Bubble Cloud" and "Bubbles/Clock:Show/Hide".
If these items are in the app list on my watch, there is a problem in WatchMaker editor:
The list of apps, mentioned above, shows only top apps from the list. Only those, which are appearing before the item "Bubbles/Clock:Show/Hide" (the item itself is also not shown).
So I cannot select any application, but with name starting with 'A' or 'B' (before "Bubbles").
I believe the problem may be caused by slashes ('/') or colon (':') in app name.