How to know that my phone is hacked?

Answer 1

The "inc" article is more focused on compromise indicators; I'd take that one. From the other, the apparent safety of jailed systems assumes the jail is working properly. Apple's jail policy pre-cripples any app that could have helped you when the jail seems fine but isn't, and again the "inc" article is more focused on knowing when this has happened.

Using the second article + what you know, prove the null hypothesis => "my phone is not hacked" (explain everything as the normal outcome of something expected).
Whatever survives this skepticism is interesting because it's a blind spot in your knowledge or it's truly abnormal.

Developing this skill will help you debug program/code behaviors too.

Answer 2

https://www.techlicious.com/tip/how-to-tell-if-your-phone-has-been-hacked/
https://www.inc.com/joseph-steinberg/14-signs-your-smartphone-or-tablet-has-been-hacked.html

Answer 3

How about you tell me what lead you to think this in the first place?

Answer 4

You don't.