I checked it twice
It should not be that way.
That is winbox connections to 4 different routers:
Lower 3 have no open windows, only cpu/time/date/etc in the dashboard.
Upper one has an open IP --> Firewall --> Connections
from where I took a screenshot.
So it never rises over 5kbps/10kbps (To winbox/From winbox) for the ones without windows open.
So check again that it is a single winbox connection and not something else on the router.
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