This is a hybrid politics/international law question and it’s posted here for convenience.
Everyday interactions would include border crossings, postal services, telecommunications, airspace navigation and visits, banking, staffing of UN agencies and other foreign offices resident in Afghanistan, etc.
Notably, since August 2021, several countries have even sent officials, on publicly announced visits to Taliban leaders without anyone switching.
Remarkably, it seems that most, if not all, countries still officially maintain the previous administration as the official government almost a year later, at least there are no public denunciations that I could find.
Especially, it doesn’t seem credible that border crossings, internet, satellite and phoneline connections, bank wires, aircraft landing permits, postal services, and so on could be carried out for almost a year without someone, somewhere, signing a document that assumes the authority of some agency or representative of the Taliban.
The only way I can see to square the circle would be if there's a mysterious roundabout way of avoiding this on the official paperwork (communications, agreements, etc.) and in on the record meetings.
How are countries who have interactions avoiding the obvious?
In the case that they accept the obvious but nonetheless refuse recognition, what do they gain from admitting dozens, if not hundreds, of Taliban representatives and agencies hold real authority while denying it for the overall government?