Hello all - I always close my flightplan via the SD portal if landed in an uncontrolled aerodrome and/or my last FIS is closed (Was a night flight the other day coming home and Geneva information was tucked in bed...)

I‌ then got a call from Swiss Control saying my flight was still open and asking if I was safe.‌  Does this mean we can't trust the close flight plan feature on SD?

Do I need to call Swiss Control regardless?‌