SPICE password-secret doesn't seem to be recognized

[J]

Hello all,

I ran into an issue with the password-secret option of SPICE on QEMU. I tried 
implementing the instructions of 
https://www.qemu.org/docs/master/system/secrets.html to store the SPICE 
password inside a plaintext file. This prevents it from being passed at the 
command line.

This works:
-   SPICE without passwords (disable-ticketing=on)
-   passing the password directly in the start script (password=lol)
-   setting a password manually at the QEMU monitor (set_password spice lol)

This doesn't work:
-   using the password-secret option

More detail:
Inside my startup script I have got the following commands:
----------
-object secret,id=password,file=password.txt,format=base64 -spice 
unix=on,addr=/run/user/1000/spice-windows10.socket,disable-ticketing=off,password-secret=password
----------
The password.txt file is stored in the same folder as the startup script. I 
tried both with and without base64 encryption but that shouldn't matter as my 
testing password is all ASCII (lol).

Errors:
The process itself doesn't print any errors. When I open remote-viewer to 
access the vm I am greeted by the normal password field. The problem is that 
typing in the password fails.

Can someone help me?

Regards,
Johannes