[DW 15 and 19 on macOS] Site Definition is loosing the Login Data after a restart

Hi.

When I define a site in DW 15 or 19 on macOS everything works fine and I get a positive result after testing the connection. I set the checkmark for save. I restart DW.

Result:
The Login Data are gone. They haven't been saved.

I can reproduce the problem.

I used a workaround to solve it: I duplicated the the site definition (it was an imported one).
With the duplicated definition it worked, it is saved as expected.

Is that a known bug?

Is there may be a workaround for the import of site definition in form of a manipulation of the file rights/permissions?

Independent of that:
In DW 19 I can choose the "FTP via SSL/TLS - explicit Encryption". It works fine.

In DW 15, with the same webserver and the same login data, it does not work with that type. It only works with the Type "FTP".

Is that a known bug in DW 15?

Thanks for your help?