Linux/Steam won't install games in custom folder?

[luharcas]

Steam on Linux Opensuse Tumbleweed

I have an additional SSD mounted in /home/username/games/. I can read/write to it, so theres is no problem with access rights.
I added this folder as additional library. Steam had no problem putting its "infrastructure" creating /steamappos containing /common, /downloading, etc into this new folder.
When I want't to install a game there, it creates the game folder in steamapps/common/ and then after some "deliberation" it just quits the whole thing with "download failed".
BTW, if someone may think its a general problem with the downloads, an install into the default Location, works without problem.

Why may that be? Help? Please?