Comcast Email Issues - Incoming emails can sometimes take from 1-6 hours or even more to be delivered

I am experiencing significant delays in receiving email, very sporadically for the past several weeks. An incoming email can take from 1-6 hours or more to reach my inbox, as confirmed by the time stamp. For example, a manager might send a group email to the team of 12 at 8:30 a.m., and I cannot see the email until 11 a.m.  The only way I know that I have not received the mail is that other recipients Reply All to the team, and I can see the manager's original email at the bottom of their mails. This makes it very hard to work as part of a team, where responding in a timely manner is very important.  Note that this occurs no matter which email client I use on my Windows 11 desktop or iPhone 12 Pro. The emails do not show up when I look at mail via gmail, phone Mail app, Outlook on desktop, etc. and even when I log into Xfinity and access my comcast.net mail straight from the source. What gives?  How can I resolve this horrible issue. I have had comcast.net for eons and do not want to switch to another carrier. Surely there must be some issue with the receiving IMAP server?  Please advise. Thank you so very much. Jmg