The translations on macOS work fine in the login window (tlclient), but not once connected (vncviewer). Haven't determined why, but I suspect the nested bundling is an issue where vncviewer fails to find the .mo files.
*** Bug 7523 has been marked as a duplicate of this bug. ***
It looks like we've simply forgotten about macOS when we compute the location of the locale dir. We only have code paths for Windows and "other", which seems to assume the Linux directory layout.
Works well. I could reproduce the issue on macOS 11.6 using Swedish system language and the 4.13.0 client. The F8 menu and Options were not translated once connected. Verified that things are properly translated when using the nightly (build 2271) client on the same machine. Code changes and release notes look good.