Both are set to "deu8". I checked properties : 

The only difference is in collation tables. Both are set to "German2", but "Additional" column is not the same : 
CACHE : Cache standard, German1, German3
IRIS : German1, German3, German5, IRIS standard
I guess that's the reason. Not sure how it can be fixed (so CACHE behave like IRIS). All "edit" buttons are grayed.

Both servers have region set as "German (Switzerland)". I checked the rest (eg: "Time, Date, Advanced settings", ...) and everything seems 1:1. Is there a specific setting I should check ?

I forgot to mention I am on Windows.

"iris terminal" works somehow. There is several issues with this approach :

- it does not redirect input/output (eg: echo 50 | iris terminal IRIS). One workaround is to put commands into a routine and call it explicitly : iris terminal IRIS MYROUTINE %SYS

- it does not block/wait until completion (which is an issue since I use that command from a deployment tool that need to know once it's done)

- there is no way to provide custom credentials (eg: execute commands with a specific user)