The release notes for S132 v6.1.1 lists a bug fix:
"Fixed an issue where NRF_TIMER0 may not be reset at the start of a radio timeslot (DRGN-10650)."
Did this bug exist in S132 v3.0.0 or was it introduced more recently? I'm wondering if an existing project using S132 v3.0.0 might be affected.