BLE connection closes after a few minutes

I have a hobby project where my puck.js sends accel data:

Puck.on("accel", function (a) {
  var accel = a.acc;
  accel.name = "acc";
  var gyro = a.gyro;
  gyro.name = "gyro";
  var magnitude = {}
  magnitude.name = "mag";

  console.log(JSON.stringify(accel));
  console.log(JSON.stringify(gyro));

  magnitude.value = Math.sqrt(accel.x * accel.x + accel.y * accel.y + accel.z * accel.z);
  console.log(JSON.stringify(magnitude));

Then I have a python script that uses bleak to connect to the puck, and listen for that console output, which I then pass along to another toy program.

    print ("Connecting to puck " + puck_device.address)
    async with BleakClient(puck_device.address)  as client:
        await client.start_notify(UUID_NORDIC_RX, uart_data_received)
        await asyncio.sleep(100000000.0)  # Keep the connection alive
    await ws_server.wait_closed()

This all works fine for a while, but i've noticed that after a few minutes the speed of the accel data i'm getting starts to slow down, and eventually the connection drops.

Any suggestions on what might be happening? I looked into trying to do this by purely advertising the IMU data and not making an actual two way connection, but it doesn't look like I get a very high frequency signal that way. Just a few updates per second, and I need closer to 10 updates per second.

Thanks! p.s. i'm new to BLE so might be doing this a bit backwards.