Unknown managed network on my phone

I have spoke to apple, tmobile and spectrum (my internet provider) and none of them can tell me why I have a managed network on my phone labeled “spectrum”. It is not my home wifi. I have never tried to connect to it. But multiple times a day, it gives me a notification (whilst I’m not even in my settings) that my password is incorrect- for this unknown managed network. Apple advised me to have my phone inspected, but I just got a new phone and it was happening on the old one too. Nonetheless I took it to be inspected and the guy told me that it’s not the phone, as it was happening on my old one as well (which I knew). I’m at my wits end. Would deleting my Apple ID and making a new one work? Is that avoidable? Any ideas on what to do would be appreciated.