No credit for guardian quest

i HAVE COMPLETED THE GREATER RIFT LEVELS 70 AND 75 BOTH UNDER 3 MNS BUT NOT GOTTEN THE CREDIT FOR IT IN THE GUARDIAN CHALLENGES

Those aren’t Guardian Challenges.

You need to level 3 gems to 70.
You need to complete a T13 Rift, not Greater Rift, in under 4 minutes.
You need to solo a Greater Rift 70 (which you did).