Hello,
At first, please, make sure that the FIRC, SOSC, and SPLL clocks are disabled in VLPS mode. If not it may lead to the mode transition to fail.
Please refer to the section "27.4.4 VLPR/VLPS mode entry"
"When entering VLPR/VLPS mode, the system clock should be SIRC. The FIRC, SOSC,
and SPLL must be disabled by software in RUN mode before making any mode
transition."
The FIRCREGOFF bit is not being correctly configured in the SDK v0.8.6.
Thank you.
Best Regards,
Diana