WINSCP 5.16.5 RC overall speed slow

I'm a long time user and never had any problems with WINSCP until today after I updated Windows 10 and WINSCP to 5.16.5 RC. Overall speed is too slow something I never experienced before. I tried the recommended fix at https://winscp.net/forum/viewtopic.php?t=25705 and upload/download speed improved but overall speed is really too slow as never I experienced before.

What version of WinSCP were you using before? If you downgrade, do you get the speed as before?

Yesterday night I reinstalled 5.15.9 and everything is back to normal.

Can you post a full session log file showing a file transfer, both in 5.15.9 and 5.16.5 RC?