Nextcloud AIO Workflow Only Numbers in PDF

Hi at all,
with Nextcloud AIO 25 I switched from “pure” Nextcloud (docker) . I think this is the realy best i’ve ever seen. Many thank to developing this.
But I have a little Problem with automated Workflow. With pure Nextcloud it worked. But with AIO it looks strange. The PDF ist generated when Filename is “/^testpdf*/” that works.
But a Character ist displayed as a block, Numbers are OK.
To get the Workflow work, I added
- NEXTCLOUD_ADDITIONAL_APKS=libreoffice libreoffice-lang-de
to my docker-Compose.yml

While Converting, a error is logged:
Fontconfig error: No writable cache directories
But I don’t how to fix this.

Workflow Problem Excel

Thanks for any hints, to fix this.