Samsung 970 Evo Plus 2TB slow write speed

[sampojar]

I have this drive as a Windows 10 system drive and the read speed is about 3300MB/s, but the write speed is only 2000MB/s. I think it was higher at some time, but I'm not sure. What can be the cause of that? It's advertised with 3300MB/s write speed. If I copy a big file from my other SSD (Samsung SSD 980 PRO 2TB), the speed is slow right at the start of copying and DiskMark64 also shows the slow speed.

[KarlR82]

I bought several T7 Shield of 2T and 4T, from different stores at different times, and ALL of them after not being used for a few months only deliver a Write Speed of LESS than 2 (two) MB/s. I have read about this issue in many postings. What can be done other than reformatting the drive ??  I have tried writing to them for many hours at less than 2 MB/s, and the speed does NOT change. NOTE: reading speed is still good enough, between 300 MB/s and 600 MB/s.  This is on Windows 10 and 11, and I have all the recommendations about drivers, settings, etc.