Mythic+ weekly chest reward question/bug?

Hi guys

So on Wednesday in my chest I got a:

Eyir's Blessing (Holy relic, 865, Mythic 6 Warforged) Keystone Court of Stars +7

I *think* last week I did a +8 or 9, which would make the keystone correct and the loot too low? Or even if I did only do a 6 why do I have a 7 key?

In game tickets seem to think its all fine. Any ideas?