Hi
I suggest you install the language package again for a check.
The language package can be downloaded from: https://support.microsoft.com/en-us/office/language-accessory-pack-for-microsoft-365-82ee1236-0f9a-45ee-9c72-05b026ee809f
After installation, please open Visio, click: Options > Language > Office display language, find "Dutch" and Set as Preferred, the "Dutch" will be shown as the first one.
Then please restart Visio for a check.
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