Using Classic Outlook on Windows for personal email, calendar, and contact management
I had the same issue -- events not syncing FROM outlook into google. I tried removing and then re-adding the same .ics link to my Google with the same results of newer events not showing up.
Here's what I did that fixed it (for now):
Follow instructions from before for publishing your Outlook Calendar. You should then see your previously published outlook calendar link. REMOVE that link. Then re-publish your calendar and get a new .ics link. Add that into Google. That is now working for me. For some reason, Outlook stopped pushing updates to the old link. Seems more widespread than MS may realize. Hope this helps others --