Robocallers spoof (fake) with fake return phone numbers and heaven help you if a robocaller is using your number. There is unlikely to be an issue with your phone. It's more likely some robocaller is using your number.
Spoofing is well documented so I'll stop here.
So this one is unique. I'm not pocket dialing nor is someone using my phone to call people, but I'm receiving phone calls from random people claiming I'm calling them. There aren't any outgoing calls on my phone to suggest that it came from my phone. Any suggestions would help.
I also looked for the "unkown sources" option on my phone to see if it was turned off/on, but that is gone.