Outlook 365 - cannot change email account data

Dell 660 PC/Windows 7 Home Premium w/SP1 64-bit.

I figured I'd update from Office 2010 to Office 365 but have run into a problem with Outlook. All of my accounts, calendars, etc. seem to work just fine but I cannot change any information in any of my accounts. Help says to go to File > Account Settings > Account Settings, select account and select Change. All that works but the only dialog box I get is a single box and can only change under General Settings:
Your name
Account name
Reply-to-address
Organization

and Mail settings concerning leaving message on server or not.

I have to open my old Outlook 2010 to make any changes to servers and/or connections.

I've emailed the Microsoft help guy that aided me in the purchase and installation several times with no reply.

Can the information only be changed as the Help screen shows under Windows 10?

Attached are results from both Outlook 2010 and Outlook 365 when trying to change data. I have a number of email accounts and all react the same way.

I can kind of understand that if both versions are running at the same time there could be errors but I have never run both at the same time; only both are installed. What I don't get is why I can modify existing accounts with the old version but cannot modify those same accounts and even new accounts created with 365. I'd sure hate to remove Office 2010 and find out I still cannot modify any account information and then have to recreate any account just to change settings.

Ranger4 said:

What happens if you press the "Reset Mail Settings" showing in the last screen shot of your Post.

Actually, nothing unless I do something small like changing the number of days to leave on the server, i.e., if I change from, say, 14 days to 7 then click the "Reset Mail Settings" it goes back to 14.