Phone dials contacts while simultaneously receiving an incoming call from them, neither of which are initiated by us

I have an iPhone SE (2022; 3rd generation), updated to the latest version. This problem has been plaguing me for almost a year if not more.

I will be receiving a call from someone on my contact list. When I pick up, all I hear is silence. If I ignore the call, it goes to voicemail and I receive a 1:00 message of static noise. At the exact same time, the contact that I am receiving a call from is experiencing the same thing from my number. It then becomes a game of "you called me" and "no I didn't, you called me". This happens at any time of the day, some days more frequent than others. I put my phone on flight mode when I go to bed, and there have been instances where upon disabling it, I get a text notification that I missed a call from a friend, and they tell me that I rang them up while I was asleep and flight mode was on. Also upon examining our call logs, we only see incoming calls from one another, but no sign of outgoing calls from our end.

Here is everything I have tried to do with no avail:

• Explained the problem with my phone carrier and did the following:
  • Changed my phone number
  • Changed my mobile plan
  • Changed my Apple ID password
  • Changed my SIM to eSIM
  • Factory reset my phone, and set up WITHOUT backing up
• Explained the problem with Apple Support and did the following
  • Went to the Genius Bar to do a hard wipe of the phone and reinstall the software (this being different from a factory reset). Also followed by setting up WITHOUT backing up
    • Note that this seemed to have fixed my problem for around 2 months, and only recently has it started again.

Everyone online is saying it is a spoof/prank service, but I am almost certain it is not. After changing my phone number, I only told a couple of trusted family and friends, and shortly after it started dialling out between me and my contacts from my contact list again.

Maybe some of these don't make sense but I am trying my best to understand what might be the cause. Is my issue a software or hardware issue? I would appreciate it if someone could confirm or debunk what I think might be the cause:

• An old battery; mine is currently at 81% capacity
• Phone usage habits; I use my phone when charging and it gets really hot sometimes. Also using the GPS in the car in the summer subjects it to even more heat and direct sunlight
• A corrupted file in my iCloud
• Just an unfortunate case that is out of my control and it is time for a new phone

Other than this issue my phone is completely fine. I would love to keep using it as it is not that old, but if buying a new phone is the solution then so be it. My main worry is that the problem is not with the phone itself and that the issue persists even after buying a new one. Has anyone experienced the same thing as me and how did you solve it?