Here is the problem that I had with my ground weapon action buttons.
For the longest time when i would zone into a ground instance my weapons buttons would be missing from the interface. My other buttons remained the same (kit powers and devices), but my weapon buttons would vanish.
For a day during the head start the buttons worked perfectly but that was patched away.
For the last few days I've had the issue where the weapon buttons wouldn't disappear comepletely but would be on random empty buttons.
I would right-click drag to remove the buttons on the wrong spots, then re-drag the attacks from the 'p' abilities box to the action buttons I prefered.
And that was the mistake that I was making, and what some of you might have been doing.
Here's the solution that I found.
step 1. Open up your ground action bars to show all 3 rows. What you are looking for is the 'missing' or 'wrong spot' weapon attack buttons. In my case the melee attack was on the top row and my shots were on the second row.
step 2. Right-click drag the attacks from their current locations to your desired spots. It seems that weapon attacks dragged from the 'p' Abilities window do not stay after logging into space.
NOTE: If any of your weapon attacks are not showing when you show all 3 action bars it is because your other powers (kits and devices) are occupying the actoin button that STO assigns as its default. If you have this issue then drag off your other attacks then zone in and out of Sol Space dock to find the hidden weapon attacks. Its a little work, but its better than reworking your action bars everytime you ground zone.
Since I did this I have yet to have an issue with my action bars.
Hopefully this will help some of you with action bar issues.