Outlook Hanging on IMAP "Synchronizing Folders" -- Switch to POP?

Hello! Need some help figuring out IMAP vs. POP email accounts please. I just got a new desktop PC with Windows 10 Pro. When I set up my Comcast email profiles in Outlook 2016, it automatically set them up as IMAP accounts. 

Now my Outlook email is hanging on the "synchronizing subscribed folders" function, which I didn't have on the old computer (which also had Outlook 2016 -- but using a POP account with Comcast).  Is there a way to disable this "synchronizing" function, or do I need to switch back to the POP accounts? I have one Outlook profile for a work client that uses Office 365, so I don't want to mess that one up (as guessing that's also an IMAP account). But thinking my two personal Comcast accounts -- which I only use on this computer (not on any other devices) might be faster as POP accounts. Help? THANK YOU!