You’ll likely have multiple refreshes on some objects which triggers this notification multiple times and thus also show up multiple times. See if you can do something about your refreshes to 'fix' it.
Otherwise you can also copy the microflow which contains the refresh on the user and make one without the refresh, to at least get rid of one.
- add a counter / helper / attribute to know it is shown for the first time or not
- and if shown before ($counter>1) don't execute the message logic when the counter is over 1,
- or dont show the widget by a conditional expression when the counter is over 1, or some thing like that