Pretty cool sw called rayhunter to detect cellular spying and you can flash it on Orbic device.

Overall you can pull this off within $70 price range.

It gives you a color signal (green - all is cool, or red - probably IMSI catcher in your close proximity)

https://www.eff.org/deeplinks/2025/03/meet-rayhunter-new-open-source-tool-eff-detect-cellular-spying

HW: https://www.amazon.com/RC400L-Carrier-Unlocked-Mobile-Hotspot/dp/B0F45RXZCW