I have been in Turkey for a month and using my Mastercards with both Monzo and Starling bank in the UK perfectly. However about a week ago, all online or app payments with my two cards were not being authenticated or recognised by the vendor. I would authenticate normally in my bank’s app, but then when I was redirected to the vendor, all payments would fail.
This is a mastercard issue because it has happened across three separate companies in Turkey (Turkcell, BiTaksi, iTaksi) and across two different UK Banks. The only common demoninator is 3ds Mastercard.
Can Mastercard investigate this issue as a matter of urgency and resolve whatever needs resolving. I can't make payments through the taxi app which means handling cash which is not secure at all due to Covid.