Walking profile with walkway/alleyBias=1 create 3x longer routes than expected

Hi all-

I am using turn-by-turn navigation with the Mapbox DirectionsAPI on Android and explore strange routing behavior when selecting the "walking" profile. Some routes are 3x longer than a comparable cycling route, especially highway=path and =footway seem to be avoided at all cost. I also pass walkwaybias=1 and alleybias=1 but it does not change the behavior.

An example here:

1. Walking Route: https://codepen.io/ulnn/pen/RwrYbja
2. Cycling Route (better route, but still mediocre): https://codepen.io/ulnn/pen/eYJLOKb
3. Best Route (desired outcome): https://www.openstreetmap.org/directions?engine=graphhopper_foot&route=50.13981%2C8.69852%3B50.13825%2C8.69507#map=18/50.13921/8.69745

Any idea?

まず、リンクされたCodePenページの徒歩および自転車の例を、Android上でMapbox Directions APIを使って再現します。リンクされたOpenStreetMapのルートと動作を比較し、walkwaybias=1 と alleybias=1 が適用されているか確認します。実行可能な原因または確認済みの制限を特定し、期待されるルーティング動作を文書化できれば完了です。