Launch: AA hits not firing in Dev environment

I have this strange problem with Launch. I’m setting up a new property and have already setup my data elements, rules, extensions etc. I've created the library and published my changes to Development.

In my dev site, I can verify that it’s loading the dev Launch environment. Using Experience Cloud debugger, I can see Launch's Adobe Analytics-related logs, ending with

[Adobe Analytics] Applying the following properties on tracker: "..."

and it lists all of my props, evars, etc

BUT there are just no hits going out to my tracking server!

Strangely, I could see hits when I had first published my dev library and browsed my dev site. But then, I tweaked the AA extension (updating the list of "Never Track" items), and rebuilt my library. From then on… no more hits!

To ensure that the .min.js file was being updated with each publish, I opened it directly in my browser. Then I republished the library. When I reloaded the .min.js, I saw its buildDate update to the current time. So the publishing is working too.

FYI I’m looking for hits in both Experience Cloud debugger and my browser’s network console (filtering for /b/ss).

What could have gone wrong?