AFAIK theoretical sampling rate limit for SISO mode is 61.44 MHz, which means that in MIMO mode you’ll get at most 30.72 MHz. That’s theory, in practice even with very powerful machine 25 MHz in MIMO mode is often as far as you can go without dropping packets (and that’s just sending/receiving samples, I’m not even talking about processing them in any way). So, looks like your sampling rate is too high and that’s why you get your late packet indicators.
