This is something I have seen for a long time, its annoying but there is a work around that I use. When tagging a switch port via the switch menu I find that the field doesn't auto populate which I think it odd.
To get the field to auto populate you have to add tags via the switch port menu. Examples below
Meraki CMNO, Ruckus WISE, Sonicwall CSSA, Allied Telesis CASE & CAI