Different dialog boxes for share links in web interface

When I use the web interface to share a file or folder I get randomly two different dialog boxes:

This is the one I would expect…

…but sometimes I get this one:

I cannot see any pattern in this behaviour it looks random to me. Server version is v6.0.2 Pro, my web browser is Safari Version 10.0.2 (12602.3.7). I have activated memcache.

Any ideas ? A bug?

The first on is the dialog which will appear, when the file/folder is not shared yet (So you can generate a link).

The second one will appear, when the file/folder is already shared (Meaning a link was already generated).

When you click “Generate” in the first box, you will get the second one

Ah interesting, thank you Jack, that was new to me.