As a workaround, the ssh key could be explicitly set by IdentityFile in %userprofile%\.ssh\config.
For example, to set one key for all hosts, these lines can be added to the %userprofile%\.ssh\config file:
Host *
IdentityFile C:\Users\[yourusername]\.ssh\id_rsa
Before adding lines, [yourusername] should be changed to the actual user name, and id_rsa should be changed if the required ssh key has a different name.