6* Sig stones objective disappeared

Hi guys, my 6* Sig stone objective for doing incursions has disappeared. Like the "Summoner's Journey" objectives it had no expiry timer on it and I planned to complete it this month.
Does anyone know what happened to it? It definitely didn't complete them so they should still be there.
Does anyone know what happened to it? It definitely didn't complete them so they should still be there.
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