After a little more time spent with the bass:
Still trying to dial in the setup. Made some adjustments to action and relief. I noticed that the nut appears to be cut too high. When I’m able, I’ll get a pro setup.
There’s also a grounding issue, a buzz that goes away when I touch the strings or bridge. I’ll also get this taken care of when I get the setup done
The pickup was rattling around in its cavity when, for example, I pluck the G string. I tweaked the pickup adjusting screws to make it firmer, but it doesn’t feel like there is enough upward pressure on the pickup. Has anyone taken the pickup out who could tell me what’s in the cavity—springs, foam, etc?