I tried to install a new dictionary following the instructions. However, cspell.nvim does not seem take the new dictionary into account. Weirdly, if I run cspell through a term manually, it works as expected. Thus the result is something like this:

At the top, you see cspell.nvim's highlighting through null-ls. At the bottom is the cspell output.

"Katze" (cat) is a German word. German words are generally case sensitive, thus "katze" is expected to be incorrect. "clearlynotaproperword" is just there to check that incorrect words still recognized for English words and "english" is a correct English word. "acustomword" is a word I added to the cspell.json to check that the file is used at all by cspell.nvim.
cspell as an external command works as intended. cspell is not installed on the system, it is installed only for nvim with mason.
cspell.nvim does not take into account the imported file. It does recognize the custom word added manually to the config though.

Last but not least, the cspell.json:

{
    "version": "0.2",
    "language": "en,de",
    "import": [
        "C:\\Users\\[my_user]\\AppData\\Roaming\\npm\\node_modules\\@cspell\\dict-de-de\\cspell-ext.json"
    ],
    "words": ["acustomword"]
}

I'm on Windows 11, if that changes anything. The issue is the same on powershell and cmd.
Any ideas what might be going on?