BTTCUSDT: bnb discount not working for "BUY" order

API Spot/Margin API
1

For some reason, the BNB discount on the buy order does not work on this pair.
At the same time, it works on a sell order.

3

The same problem on BTTCTRY, PEPEUSDT, PEPETRY, PEPEFDUSD, PEPETUSD.

4

2 weeks have passed, no changes.
Is this a bug or a feature? ?