hi, as tilte i got a problem with my exp points when i'm farming/killing enemies.

i got always the x7 exp on killing creatures, but when i hit the lvl 80 i didn't got it:from the same creatures i got 780 exp instead of 6.000 more or less, i tryed to change zone and it is the same, i tryed to lvl up for a level, now i'm 81 but i got the same problem:extremely low exprate (feels like x1)
what can i do for it? thanks for the answers