Trying to understand how to increase my Defense Index (Kebir Blue)

I'm improving all indexes except defense and seem to be stuck.

I've spent buckets of money on defensive weapons of all kinds, but that seems to have no effect on my Defense Index. So I reasoned that they must somehow be deployed once obtained, so I tried setting up garrisons. But in all cases, even though several real-time days have elapsed, all garrisons show as "planned" rather than actual.

I'm also wondering if supply units affect the Defense Index.

Any clarifications/suggestions welcome and appreciated.

The Defense index is a moving average, so depending on what you bought and when it got delivered, it may take awhile to move.

Also, note the timeline. You purchase weapons in game - it may take 2 or 3 game weeks to execute, then you have to wait for the next update cycle to go through, plus it is a moving average.

There could be quite a lag between entering the order and having the index move.