close - IO is still pending on closed socket. read:1, write:0, io:0000023DE45AF900

"OpenSSH for Windows" version

1. OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2
2. OpenSSH_for_Windows_8.6p1, LibreSSL 3.3.3

Server OperatingSystem
Ubuntu 18.04.5 LTS

Client OperatingSystem
Windows 10 Enterprise

What is failing
In my company, I have two PCs in the company network given by IT.
I usually open a CMD window and connect to remote Linux server with command ssh <account>@<server>.
However, I found that on my PC1, after disconnecting from remote Linux server, the ssh always shows the following error message at the last line:
close - IO is still pending on closed socket. read:1, write:0, io:0000023DE45AF900
But on my PC2, it never does that after disconnecting from the same remote Linux server.

I also tried to connect to other company remote Linux servers from the two PCs, but the results were the same as above.
So it seems that the problem is not on the remote side, but on the local side.

Besides, I tried different ssh toolchain versions.
The Windows 10 built-in ssh client version is OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2.
I downloaded the latest ssh toolchain version OpenSSH_for_Windows_8.6p1, LibreSSL 3.3.3, unzip it and set up PATH env variable, and tried again on my PC1.
Both versions shows the same error message after disconnection.

I would like to know how to fix this issue.

Start by reproducing the disconnect on Windows 10 Enterprise with OpenSSH_for_Windows 8.1p1 and 8.6p1 against an Ubuntu 18.04.5 LTS server, then compare the two PCs and the resulting socket behavior. Done means identifying a reproducible local cause and preventing the "IO is still pending on closed socket" message after disconnect.