If you see the error message 100421 on BingX, then this market is probably in cancel-only-mode. Where no new orders can be placed, but it’s still “active” for cancelling. Or something similar.

We have no way of detecting this situation. When they say it’s an active spot market, it’s an active spot market.

Example of what such an error message looks like on Cryptohopper:

04/03/2024 1:05:02 PM  ERROR  {"code":100421,"msg":"The symbol you request is not available to place order currently, please verify symbol's status in api:/openApi/spot/v1/common/symbols","debugMsg":""} Errortype: ExchangeError