From the "LMS7002M DataSheet" -
"RX analog filters are tunable from 0.7 MHz to 80 MHz."
"The TX filtering chain pass band is tunable from 2 MHz to 80 MHz"
So 48kHz samplerates in your flowgraphs is not good.
Those error messages are coming from here at a guess, and the limits look to be slightly different than those defined in the LMS7002M datasheet:
Another thing you may want to look into if the noise is still present using sensible sample rates is to try a USB cable with better shielding, noise could be coming from USB 3.0. Or from the PC, try moving the LimeSDR further away.