it may well be a firmware issue, in that case have a look with magician to see if the drive's firmware is up to date, if so you unfortunately need to wait for a firmware update to fix the issue 😞
I have a 970 Evo with the same issue, but way underperforming.
I have write speeds at 940mb/s at best.
HW monitor found a peak at 3085mb/s, but only for a second, the medium is 880mb/s, this is awful!
I checked the comments above and don't think that it is a firmware issue, as it performed well for some time after I installed it. My bet is on a Windows 11 update of some sort, this OS has been giving issues with M.2 also in the beginning.
Anyone had some further follow-up on this?