Running Offline Tiles Server + PyDeck viewer

[aka-sova]

Hello!
I am struggling for several hours to solve this, would appreciate any help. Tried using any possible AI for help, with no success.
I have offline machine where I need to display some maps. I downloaded tiles (zoom 0-7). The server with tiles seems to be running well, and I can access each tile via URL in the browser. When I try to run the PyDeck client (I try to visualize it with streamlit), there is only black screen instead of the map. I see that server does send the .png images to the client! But they don't display.
What am I doing wrong?
Thanks!!

PS. I attached the Tiles files for your convenience
tiles.zip

• Server Code:

from pathlib import Path

from flask import Flask, abort, send_file
from flask_cors import CORS

# Root directory where downloaded tiles are stored
TILE_ROOT = Path(__file__).parent / "tiles"

app = Flask(__name__)
CORS(app)

@app.route("/tiles/<int:z>/<int:x>/<int:y>.png")
def get_tile(z: int, x: int, y: int):
    tile_path = TILE_ROOT / str(z) / str(x) / f"{y}.png"

    if not tile_path.is_file():
        abort(404, description="Tile not found")

    response = send_file(tile_path, mimetype="image/png", conditional=True)
    # Prevent long-lived browser caching so offline tests reflect server state
    response.headers["Cache-Control"] = "no-store, no-cache, must-revalidate, max-age=0"
    response.headers["Pragma"] = "no-cache"
    return response


if __name__ == "__main__":
    # Bind to all interfaces so other devices on the network can access it
    app.run(host="0.0.0.0", port=5000)

• Client code

import pydeck as pdk
import streamlit as st

# URL for tiles served by offline_tile_server.py
TILE_URL = "http://localhost:5000/tiles/{z}/{x}/{y}.png"

st.set_page_config(page_title="Offline Tiles Viewer", layout="wide")
st.title("Offline Tiles + pydeck")

# Build layers
layers = []

# NEW: Enhanced TileLayer for better offline coverage/debug
layers.append(
    pdk.Layer(
        "TileLayer",
        data=TILE_URL,
        min_zoom=0,
        tile_size=256,
        extent=4096,
        tile_format="png",
        pickable=True,  # NEW: Enables interaction
    )
)

view_state = pdk.ViewState(latitude=0, 
                           longitude=0, 
                           zoom=0, 
                           pitch=0, 
                           bearing=0)

r = pdk.Deck(
    map_style=None,
    map_provider=None,
    layers=layers,
    initial_view_state=view_state,
)

st.pydeck_chart(r, use_container_width=True)

Thank you in advance!!!