Sending, receiving, and organizing email in Outlook.com
This is the exact behavior I am seeing as well. It was working until a few days ago on the website, and now I see the exact same thing that you are seeing. Connecting my gmail account in the outlook mobile app also works for me. The only workaround I have found for the issue with the website is to subscribe to each google calendar individually, however, for my primary calendar, it's flakey. I just cleared all of my cookies, updated Google Chrome to version 119.0.6045.106 (Official build) (64-bit), and restarted my PC just in case that was causing the issue. No luck. I am running Windows 11 Home, OS build 22621.2428 with Windows Feature Experience Pack 1000.22674.1000.0.
Please help!!!! This is causing me tons of lost time going back to looking at multiple calendars to make sure I don't miss appointments.