Netatalk/afp causes rockstor to freeze

Brief description of the problem

Enabling AFP and copying any data to it causes rockstor to freeze. No logs, no response. Hard reboot.

Detailed step by step instructions to reproduce the problem

enable afp
connect to macbook
copy file
copy errors
afp mount disappears
console unresponsive
reboot rockstor


Dell T110
vSphere 6.5
rockstor - 2 vCPUs 3Gb memory 200Gb of HDD with about 50% used (media)

Not sure what the issue is, hoping someone here has hit this before.

Samba works fine (though slow compared to NFS)
NFS works fine

Hoping to use this as a time machine target.