Hardware

Semtech LR2021 radio

Internal firmware version

FWMajor: 0x01
FWMinor: 0x18

To reproduce

1. take 2 of LR2021 nodes
2. use https://github.com/Lora-net/usp/tree/main/examples/main_examples/packet_error_rate_fsk_example example on both sides
3. change FSK_BITRATE to 1000000 in the packet_error_rate_fsk_example example source code, update deviation and bandwidth values accordingly
4. run the packet_error_rate_fsk_example on both sides - it should work nicely
5. change FSK_BITRATE to 1041000 and update both connection partners
6. the packet_error_rate_fsk_example example no longer works properly

Expected behavior

GFSK modem of LR2021 radio should work with 1041 kbps data rate (in use by ADS-B UAT @ 978 MHz in North America and UK)

Actual behavior

It looks for me that Transmitter component works fine with 1041 kbps bitrate.
1041 kbps GFSK packets sent by LR2021 can be received by an SDR radio or Texas Instruments CC1352 receivers.

However, the LR2021 Receiver component does not work properly with 1041 kbps bitrate. Received data is corrupt and looks like been down sampled to a fixed data rate, such as 1000 kbps.