At the end of the day, I would use the settings Spectrum posted online. Not addressing that issue is not going to fix anything else - no matter the other suggestions posted.
Additionally, no matter how many "different" devices, OS, or email clients you use (which causes a still rather confusing post to navigate through), the email account settings need to be the same throughout - whether on Vista, Windows 11, or IOS. Office 2021 or Windows Mail. That means if the email account is joe.blow.com, those settings need to be the same per the ISP suggestions through the myriad of devices, OS, and email clients.