Thanks for info. Unfortunately I have no solution but have a lot of evidences the SMB protocol does not work correctly on Windows 11 PRO 22H2. So, I sent the ticket to NAS Support Team and second ticket to Windows Support Team to investigate the SMB issue.
I had online meetings with Windows Support Team, they checked my Windows settings (especially network settings) and verdict is... we do not know now. The agreement is they will try to investigate the SMB issue offline. So I have to wait for Windows Support response.
However, I did tons of different test in my environment and my conclusions are as follow:
1.
Windows 11 PRO 22H2 does not inform about need of NIC driver update, what's more, Windows suggested that my current NICs drivers are up-to-date. However, it wasn't true, so I manually updated PC NICs drivers. The update resolved one issue connected to test results reported by tools like e.g. CrystalDisk. Now, this tool reports READ 570-590MB/s and WRITE 570-580MB/s in multichannel SMB env. 2x2.5Gbps. So I am closer to the proper solution BUT unfortunately it does not resolve all SMB problems (below explanation).
2.
Because of success described in point 1, I prepared 10GB file to transfer it using Windows File Explorer and Windows Commander. The test failed and results disappointed me. The same SMB issue again, the downloading transfer speed is about 200 MB/s vs uploading speed about 550 MB/s. No improvement at all. My NAS network monitor shows bizarre numbers in terms of downloading speed in SMB multichannel environment, NAS NIC LAN1 download speed is 100 MB/s vs upload speed about 300 MB/s, the same bizarre numbers in NAS NIC LAN2. It means the total LAN1+LAN2 download speed is 200 MB/s vs almost 600 MB/s of upload speed.
3.
Because of fail in point 2, I had to check my hardware (PC, NICs, NAS). I did some FTP test between PC-NAS. FTP protocol is NOT "multichannel", so my expectations are READ 300 MB/s and WRITE 300 MB/s for LAN1 and the same numbers for LAN2. The FTP test confirmed my expectations, the same max speed in case of downloading and uploading. Success, my hardware works correctly.
4
Because of success in point 3, I checked the configuration like this-> SMB multichannel OFF. According to FTP test the results should be more or less the same for SMB without "multichannel" feature. Again the results disappointed me, on LAN1 downloading speed was 200 MB/s vs uploading 300 MB/s, the same numbers on LAN2. It means that SMB protocol does not work correctly on Windows 11 PRO 22H2 at all. It doesn't matter SMB multichannel is ON or OFF the SMB downloading speed is disaster.
Postscript
To test FTP and SMB I used my main drive C (PCIe NVMe SSD drive) and also RAM Disk (memory 16GB ram disk). The results are exactly the same. So, the performance of destination disk (write operation in downloading tests) does not matter. It seems to be a huge SMB bug...
What do You think about my tests, maybe something is wrong in my approach ?