The starbase issue will be getting reported, just want to check some other things first. Although someone who feels more ambitious can feel free to beat me to it.
And further checking with the all of one Game I played during 2.7.x reproduces the problem of starbases being unable to build defenses across ALL of the saved game files, even the pre-2.7.2 version. But the issue does not seem to present with a game I started in 2.8.0
So while it is potentially a major compatibility issue between game versions, I cannot rule out the problem being something unique to the initial play session, and I'm not rolling back to 2.7.2 to find out. And as it does have a resolution path(rolling back to an older version/start a new game) whatever is causing the issue should be a very low priority fix, one I'd have no expectation of ever being fixed... So not filling out the bug report after all.
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