Thanks for the reply. I think I don't have TSA pre check on my nexus because TTP portal does not say that Pre Check incudes. I am not Canadian citizen or US citizen, so I only have Canadian PR. Will I be able to use pre check even it doesn't show?

You have to go by what is on boarding pass.

In TTP you are saying there is no
Includes:TSA PreCheck® above Membership Number/PASSID:?

Canada619 is correct. From the TTP home page, under the "Learn More" link for Nexus, the following is mentioned under the heading "Benefits":
Canadian PR's aren't included in the Nexus program for the TSA PreCheck benefit.

Which is a very asinine policy if it is actually the case, as it makes no sense to give expedited immigration and customs clearance to a group of people but not security clearance. OP is honestly one of the few Canadian PRs posing to this forum, as I’ve always been curious if the Canadian PRs not getting Precheck is actually a thing or is just incorrect or non-updated wording. OP, please do add your Known Traveler Number to your reservation and let us know if you get Precheck.

To complicate it even more. If you are a German national enrolled in GE, it appears you get Pre.

On TTP screen, GE includes Pre while NEXUS may include Pre.

I'm flying domestic tomorrow with my wife + infant.

My wife and I have NEXUS, while I've been waiting a few months for my infant to get approved (so he doesn't have one yet).

Can I still use the NEXUS lane when traveling? I vaguely recall some news article several weeks ago that mentioned minors under 18 should be able to travel with their parents, as long as both parents have NEXUS. But I can't seem to confirm this any more...is this still the case?

Domestically where, the US or Canada?

Please refer to the following threads:

There was a change regarding using the Trusted Traveler security lanes in Canada. (Plus vaguely remember change in access for US Precheck lanes when traveling with parent that qualifies for Precheck access) However no change in using the immigration lanes on either side of border.

Are you referring to security lane or immigration?

Since you are flying domestic, I'm assuming you are talking about security. In that case, infant, regardless of approval, should be able to use the Nexus lane (though if traveling with a stroller or carseat, IIRC, they tend to 'force' you into the 'family' line, at least that was my past experience transborder at YYZ when we used to do that).

There has been no change to precheck access in the US as far as I am aware. Minors (12 and under) traveling with an adult with precheck can use precheck.

Actually, there has been a recent change. Teenagers, ages 13 to 17, traveling on the same reservation as their parents can now join them in the PreCheck lanes; however, that is a topic for another thread which I linked earlier in this thread.

Thanks folks. I'm traveling domestic within Canada today. Will be traveling from Canada through the US to another country in my next trip, also with the little one.

I have Nexus, but haven't used my card anywhere yet. Can Nexus only be used at pre-clearance locations or can I use my card when arriving from Canada (from an airport with no pre-clearance) in the USA when clearing customs? YYT has no USA pre-clearance, and there is a direct flight to TPA, so just wondering if I could still use my Nexus in TPA when clearing customs there?

NEXUS includes Global Entry so you can use a Global Entry lane at any U.S. airport of entry including pre-clearance in other countries. In addition, you can use NEXUS lanes at U.S. land entry points from Canada (and can present your NEXUS card in a regular lane if there is no NEXUS land or it’s closed).

You have to bring your passport to clear CBP at TPA. NEXUS card is insufficient.