google calendar non-stop popping-up

when I set a schedule to always accept in em client calendar, I keep on getting a reminder pop-up as in the screenshot. I click on Dismiss All and Snooze All but it just keep popping up.

this is a past event, try opening it and setting the reminder to “never”.
Or, have you tried the individual dismiss in this case? Click the bell icon in the reminder itself.

yes i have tried that but doesn’t work. What works is I set decline to that event. Now it is gone and so does the event in my calendar.

Did not worked. Any of solutions. Even declined.