This issue can be reproduced by having a different language than English as primary on the macOS (10.15) and then pressing 'F8' while in the session. Nothing will be translated to the desired language. However, tlclient still translate things just fine. Tested this in the nightly build client 6516 and could even reproduce this on 4.11.0 and 4.9. Tested only having one language as the preferred language but the result is still the same.
*** This bug has been marked as a duplicate of bug 7270 ***