submodules vanished from repository view

after updating SourceTree to 1.9.6.1 (not sure from which version, definitely older than 1.9.6) existing submodules are no longer shown in the repository view. In the left column of the repository view the categories file status, branches, tags and remotes are visible, but submodules is missing, despite submodules existing in the filesystem and config.

this is a rather bad situation as we are heavily relying on submodules.

please look into this or advice how I can temporarily downgrade to an older version.

PS: when updating SourceTree the updater showed two updates, 1.9.6.1 and 1.9.6, with the former pre-selected. I did not change the selection and proceeded, could this be part of the problem?