Symbol is on delivering or delivered or settling or closed or pre-trading (error -4108)

Hello, sometimes I get this error when making a request for bookTicker information on Testnet futures. It doesn’t always happen which is the weird part, and the symbol seems to be running fine as far as I’m aware when the error happens.

2022-05-17 12:34:03,334 ERROR :: Error while making GET request to /fapi/v1/ticker/bookTicker: {‘code’: -4108, ‘msg’: ‘Symbol is on delivering or delivered or settling or closed or pre-trading.’} (error code 400)

What does this error mean? It seems vague (lots of “this or this or this”) and I’ve searched the internet for links that explain it and I haven’t found any. If I knew how to check beforehand whether or not I’m going to get it then I can fix it myself.

Thanks for reading.

Futures has 2 types of contract: Perpetual and traditional Delivery.

For delivery futures, when time closes to settlement, this symbol may not able to get symbol info as it’s preparing for delivery.

But why this kind of error appears on Perpetual contract, for example DOTBUSD:
https://fapi.binance.com/fapi/v1/depth?symbol=DOTBUSD&limit=100

This issue exists on BUSD contracts: DOTBUSD, APEBUSD etc, but not exclusively. It also appears on FTTUSDT contract for example