Processor is PIC16LF18446, interface with s2lp works fine. I use S2LP_Library from SDK 1.2.1 with some adaptations for PIC. Three boards with the same behavior - possibility of soldering error is minimal. Frequency 433 MHz, crystal 50 MHz.
The reason was the malfunction of LDO regulators due to excessive capacitance of decoupling capacitor for band-gap voltage reference of VCO regulator. Changing this capacitance from 0.1uF to 390pF have fixed the problem.
