Coffee filter is put in a funnel, under which there should be a valve. Part of the mechanism may be broken and therefore would not close. If you'd remove the thermos before brewing is finished, coffee would flow out on the table.
I made a couple of pieces to print for a closely functioning valve. Used Nylon for the bigger part, and flex A82 for the small (red) part.
The g-code is binary, for mini and requires Firmware 5.10.
The author marked this model as their own original creation.