Call just about every day around 11:00am Central time. If I answer, there's no response, and when it goes to voice mail, there's no message left (other than what seems to be random background office noise).
This is still happening on an almost daily basis, usually between 9:30 AM and 11am Central time. If you try to dial-back the number you will get a "number is invalid or has been disconnected" message, so it seems the number itself is spoofed. Definitely something sketchy going on here.
Called my work mobile phone (illegal to do for cold calls). I picked up the call, but hung up without saying anything. I could hear a call center in the background. They then called back twice more immediately after that. I did not answer. They left no message, which proved beyond a shadow of a doubt that they are cold calling scum wanting to waste my time.