I believe that is due to how https://docs.wxwidgets.org/3.0/classwx_single_instance_check... is implemented on osx.

It checks if there is already a copy of TS running, and if so, passes the new file to be opened in the existing instance, which is useful with command-line usage.

On other platforms that uses lock files I believe, I guess here it uses local ports, and osx seems to think permission is needed for that.