iPhone7 Calendar Not Syncing with Outlook (Windows 10)

I am new to the forums so please forgive me if I don't ask my question well. I am having trouble getting my calendar on my phone to sync with my Outlook calendar on my PC. I am not using iCloud, just backing up to my computer only.

I have an iPhone 7, iOS 11.2.1, a Windows 10 PC, iTunes version 12.7.2 and Outlook 2013, v 15.0.4981.1001.

I connect the phone to the computer with iTunes already launched. When the phone is recognized by iTunes, I click on it, go to Info and see that my contacts and calendar are set to sync to Outlook. I click sync and the backup and all appears to be fine. However on the last step, where it says "applying changes" I get the error "iTunes could not finish syncing XXX's iPhone 7 because the iPhone disconnected."

When I open the calendar, I see an exclamation point inside a circle next to my calendar (as shown in the 2 images attached). Please forgive me for blocking out the more personal information. I used arrows on the images to show it really is an exclamation point, not an "i".

This appears to be a 2 way street - changes on my phone are not going to Outlook and changes on Outlook are not going to my phone. But it's only the calendar - the contacts appear to sync fine.

Can anyone please offer me a solution? I am not particularly "technical" so step by step instructions would be appreciated.