The internal behavior of Git (>=2.16.0) for SSH tool detection changed and TortoiseGitPlink is not detected any more as ssh or plink compatible.
This only affects if the SSH URL contains a port or you have configured Git to use the Protocol version 2. For now, you need to set the environment variable GIT_SSH_VARIANT to ssh or configure it in Git settings using git config --global ssh.variant ssh.
In the next version of TortoiseGit 2.5.7 this will be done automatically when TortoiseGitPLink is invoked by TortoiseGit (cf. https://tortoisegit.org/issue/3139). If you use TortoiseGitPLink from CLI the setting is still needed).
Update (TLDR):
- Update TortoiseGit to the latest stable version: https://tortoisegit.org/download/
- I f you use
TortoiseGitPLinkfrom Git CLI also issuegit config --global ssh.variant sshon CLI or set the environment variableGIT_SSH_VARIANTtossh.