@bravenel I can confirm, even in f/w .120, that this behavior persists. What's more, I notice that the Dashboard app assigns Tile type "Variable String" to display a hub variable of type Boolean. (That one at least offers "True" / "False" as text options, with a SAVE button beneath, and doesn't suffer from the "Sending..." issue I'm reporting about.) I changed it to Template: Variable Boolean just now for testing purposes.
The underlying hub variable's value happened to be FALSE, but tile's initial displayed text read "Unknown". Clicking it brings up a super-tiny checkbox (it was shown in an unchecked state); checking the box and clicking "Save" results in this unending "Sending..." status.
Inspection of the Hub Variable itself (in the HE UI) shows that it is not being updated to reflect the checkbox's state ... it just stays FALSE throughout.
IMPORTANT NOTE: If you leave the Tile set to type "Variable String" and choose TRUE or FALSE from its drop-down, the underlying Hub variable's value does get updated in the hub UI.
Unexpected / undesired, no?? (It's a large part of why I haven't used Dashboards since my first report back in January.)
I've take a couple of screenshots to illustrate: