My coworker is experiencing the pink banner that notifies him of macros being disabled in Excel because the source of the document is untrusted. It is a file I sent to him via Outlook, and there have been no issues in the past with this file regarding being blocked (as recently as 6 days ago). We went through all the potential fixes: 1) Trust Center Settings > Macro Options are set to Enable Macros and Trust VBA Object Model, and Trusted Locations has the network option checked, though I'm not sure if SharePoint can be added as a location. He also tried downloading the file to a trusted location on his hard drive, and selecting the Unblock option in the Properties menu, then reuploading to SharePoint - same issue again.
I have no idea what kind of troubleshooting steps to take next. I did notice an option below Trust Center for Experiment. Experiment had some unusual options that seemed like they could be related to VBA functionality, but since we didn't know what they meant, we didn't touch them. I speculated that disabling the feature overrides might help.