Hi, I understand how this change can feel unexpected.
The update replaced the old calendar sidebar with the new My Day feature, which works differently.
Instead of clicking a date and seeing details on the right, you now need to open the My Day pane and select the date there.
This design is part of Microsoft’s move toward a unified experience across apps.
To make things smoother, try these steps: click the My Day icon in the top-right corner, switch to the Calendar tab, and pick the date you want.
If the view looks broken, you can reset it by going to View then click Reset View or running outlook.exe /cleanviews.
Quick question:
Are you using the new Outlook interface or the classic one? That will help me guide you better.
Regards,
Aron