Actions don't work at all except when "Activate on manual copy" is ticked, then they work as expected when you CTRL/C a selected string. (I can't see how to set the Version in the field above, it's version 1.2.6 as reported by dpkg in xubuntu 15.04)
Can you try whether this is still the case with 1.4.x?
In my case (Debian Stretch, clipman 1.4.1) actions only work reliably when "Activate on manual copy" is ticked. Without, it the actions menu only appears from time to time.
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