Replaced the alternator on my wife odyssey in May and things were fine until recently. Dash battery light comes on sporadically and only stays on for a few seconds. All connections are tight. Battery test strong and alternator tested good as well but the light was off at the time.
Alternator is from O'Reilly's.
Did I get a alternator with internal wiring issue?
Should I replace it?

How old is the battery?

I see the alternators fail when they warm up. .

Approx 2 years.

If you were at 3 years, I would start with the battery as that is the source of far too many electrical issues. Most times that I think I need an alternator, it was the battery.

Sorry I have not had an alternator fail that quickly before.

I'd replace the battery, likely got hammered when the alternator was failing and the summer heat has killed it

we had a '12 odyssey until march when we got rid of it due to massive/repeated brake failures that even 2 Honda dealerships and Honda corporate tech support couldn't figure out.
Prior to that we had an issue with the alternator a few years ago. It absolutely hated after market and only would take OEM.
So if you're using aftermarket that might be the issue.