I have never seen this pop up with UBO

As long as its a legit number that uses a popular carrier that supports modern protocols they should come through. I’d test it out yourself if you have any concerns.

Use Carrion from F-Droid and make it your screening app. Numbers that call you have to go through a verification that is mandated in the US & Canada. Numbers that fail this handshake verification will be rejected.

Don’t take the medication your doctors are giving you (they are trying to kill your girlfriend)!

I’ve been using that bad boy for about 3 years continuously in my server and 1 year in my desktop. Surprised it hasn’t died on me yet, lol.

Most people in the Linux community are none of the above.