Amazon Fire tv stick not showing internet

Are the Orbi router and Orbi satellite synced? I had an issue just a couple days ago where they lost sync, so devices connected to the satellite showed as connected but no internet, whereas other devices were connected directly to the router (wirelessly) and had no issues.

You could start out by going to the Orbi config page and looking at attached devices, and making sure the satellite shows up, and that the backhaul connection is listed as "good" for the satellite.

I don't have a Fire Stick, but is it possible to see its configuration somehow? E.g., the network you're conected to, the gateway, IP address, MAC address, etc? In particular, the MAC address of the access point you're connected to? (so you can determine whether you're connected to the Orbi router or satellite). Alternatively, does it show up in the list of attacked devices on the Orbi config page, and, if so, what does it say for the connected Orbi? Is it connected to the Orbi router, or Orbi satellite? You can also log onto the Orbi satellite's config page (figure out the satellite's IP address from the Orbi router's attached devices page, then type that IP address in your browser and use the same logon credentials for the satellite as you do for the router, and then look at the attached devices on the satellite's page and see if the Fire Stick is listed there.

Your Fire Stick being connected to the satellite, and the satellite not being synced with the router, is my best guess as to why the Fire Stick shows as no internet while other devices work fine. Check on that and then report back.