WinSCP re-authenticates on file save with OTP, but works correctly via SSH port forwarding

Hi,

I am experiencing an issue when using WinSCP with a server that requires a password and a verification code for authentication.

Steps to reproduce:

Connect to the server using WinSCP.
Enter the password and verification code.
Login succeeds.
Open a remote file and edit it (tested with both the internal editor and an external editor).
Save the file.

At this point, WinSCP prompts for the verification code again. If I continue editing and saving files within a short period of time, eventually the connection fails with:

"No supported authentication methods available"