Accessing WebDAV on Windows Server 2016 from outside...not working!!! Why?

Question

webdav

Help. There is a WS2016 server, two sites on ports 80, 81, for webdava I want to open a separate port in a separate folder.
I have WebDAV enabled on port 82, i.e. address: IP:82. Brandmauer access opened. Web Service and MRxDAV activated, set everything in the registry. Net * worked, the disk was created, general access was opened, to all users, authorization was allowed.
However, when trying to connect from outside, from Windows 10, or even from an iphone phone or via cyberduck, there is no connection, all the time expires.
Help, what could be the reason?