The meeting is on your calendar. You can open it, see the correct time and recognise the guests. Yet the reminder never appeared. Recreating the meeting would change the wrong thing: first find where the alert stopped.
This checklist concerns Google Calendar in a desktop browser. A phone notification follows a different route, so a reminder arriving on your phone does not prove that the computer is configured correctly.
Follow one reminder from start to finish
Open the event in the account you actually use. Note its calendar, date, time and reminder. An event without a reminder has nothing scheduled to alert you; an all-day event also deserves a separate look.
For browser alerts, Google requires Calendar to remain open. Check notification permission for calendar.google.com and for the browser in your operating system. If an alert is visible but silent, investigate sound separately. Treat that as a different symptom from no alert anywhere.
Test without disturbing a real meeting
Create a personal test event with no guests, starting twenty minutes from now, with a reminder five minutes before it. The expected alert is fifteen minutes from now. Keep the calendar open and write down that expected time.
Change only one setting before repeating the test. Afterwards, inspect the notification centre as well as the screen: a stored alert suggests a display or interruption setting, rather than a missing reminder. Check whether a focus mode was active.
Delete your test event when finished. Keep the real meeting unchanged, and record which setting restored the alert so the next diagnosis starts with evidence.