"named" keeps crashing since patching "bind" from 9.9 to 9.11 on Power LE

Issue

• After updating from bind-9.9 to bind-9.11, "named" keeps crashing with signal 6 and/or assertion failure:

named[1860]: ../../../lib/dns/rbtdb.c:10337: INSIST((rbtdb->rdatasets[header->node->locknum]).head == (header)) failed, back trace
named[1860]: #0 0x12f650508 in ??
named[1860]: #1 0x7fffa8f5d978 in ??
named[1860]: #2 0x7fffa91b2714 in ??
named[1860]: #3 0x7fffa91b9738 in ??
named[1860]: #4 0x7fffa91c3834 in ??
named[1860]: #5 0x7fffa913bb90 in ??
named[1860]: #6 0x12f6630e0 in ??
named[1860]: #7 0x12f66c258 in ??
named[1860]: #8 0x7fffa8f91c28 in ??
named[1860]: #9 0x7fffa8ab8c10 in ??
named[1860]: #10 0x7fffa86ed8a8 in ??
named[1860]: exiting (due to assertion failure)
systemd[1]: named.service: Main process exited, code=killed, status=6/ABRT
systemd[1]: named.service: Failed with result 'signal'.

• After updating from bind-9.9 to bind-9.11, "named" keeps crashing with unhandled signal 11:

[kern.info] kernel: named[17557]: unhandled signal 11 at dededededededf46 nip 00003fff89f415a4 lr 00003fff89f41554 code 30001