top output in debug doesn't show any processes

I've got a fair number of debugs from customer systems running 12.0+ that show the following for top in System/dump.txt:

last pid: 90918; load averages: 0.18, 0.23, 0.12 up 2+06:10:32 15:57:22

1262 threads: 13 running, 1196 sleeping, 1 zombie, 52 waiting

CPU: 0.1% user, 0.0% nice, 0.1% system, 0.0% interrupt, 99.8% idle
Mem: 766M Active, 566M Inact, 1415M Wired, 28G Free
ARC: 319M Total, 89M MFU, 181M MRU, 6002K Anon, 3981K Header, 35M Other
159M Compressed, 446M Uncompressed, 2.81:1 Ratio
Swap: 16G Total, 16G Free

...and then no processes.

Seems to be the same as
https://jira.ixsystems.com/browse/NAS-107267