WSL2/Windows: use external hard drive for collection

[do-me]

I'd like to use WSL2 under Windows for setting up my Qdrant instance with an external disk as storage.
I tried all possible combinations of using Powershell/cmd/Ubuntu (WSL-shell) with these commands but without success. Qdrant always falls back on my internal C drive. Note that the drive is properly mounted and I can cd into it.

docker run -p 6333:6333 -v $(pwd)/qdrant_storage:/qdrant/storage:z qdrant/qdrant
docker run -p 6333:6333 -v ./qdrant_storage:/qdrant/storage:z qdrant/qdrant
docker run -p 6333:6333 -v /mnt/d/qdrant_storage:/qdrant/storage:z qdrant/qdrant
docker run -p 6333:6333 -v D:/qdrant_storage:/qdrant/storage:z qdrant/qdrant

Only the latter command

docker run -p 6333:6333 -v D:/qdrant_storage:/qdrant/storage:z qdrant/qdrant

actually created the qdrant_storage directory. However, when I create a collection afterwards in Python and add points, nothing shows up in the directory. Instead, I can see that Qdrant falls back to using C-Drive.

from qdrant_client.http.models import Distance, VectorParams
from qdrant_client.http import models
from qdrant_client import QdrantClient

client = QdrantClient("localhost", port=6333)

collection_name = "test_collection"

client.recreate_collection(
    collection_name=collection_name,
    vectors_config=VectorParams(size=768, distance=Distance.COSINE),
    optimizers_config=models.OptimizersConfigDiff(memmap_threshold=20000),
    hnsw_config=models.HnswConfigDiff(on_disk=True)
)

I guess it's some particular Windows problem as it worked absolutely fine for me on a Ubuntu machine. Does anyone have a workaround maybe?