Open link for external file on network share is missing the "\\" in front on the path

What I’m trying to do

Hello
I’m using Obsidian on a Windows PC together with the Obsidian sync option. The “local” vault is stored on a network share “\boss\Daten[…]”. Works fine so far.
However, when I create a folder and insert a file of “unknown” type like “Drawing.dxf” then the file is displayed in the obsidian file list, BUT opening it by the related external application is impossible.
Obsidian asks “Are you sure you want to open it?”

and - as you see in the image - the "\\” in the beginning of the of the filepath is missing. Hence, opening the file fails.

Things I have tried

I played with settings-file and links-parameters without success.
Can someone help ?
Thanks

Just to add: this behavior has changed with the latest update.

I’m now on Obsidian 1.12.4. Earlier version could handle the files.