ARP setting AutocasperNbi Startup disk not working. normal netinstall works fine

[PAC]

When i try and set the startup disks of a bulk amount of imacs using Apple Remote Desktop i only get 3/25 successful for example when i use an autocasperNbi netboot that was created using @bentoms's Autodmg and AutoCasperNBI.

If i set the startup disk to a normal netboot using Apples Server's System Image Utility everything works fine.

This has been happening for over a year so it's got nothing to do with 10.13.X etc

Does anyone have any idea of what is happening or what's the best way to dig deeper to try and get bulk startup disk settings to work properly. Is this normal?

i much would much appreciate any help

Kind Regards
Pete

[PAC]

Mistake in title.
should be ARD not ARP errr :(

[reddrop]

Has the NetBoot server been trusted on each of the Macs?

See
https://support.apple.com/en-us/HT205054

[PAC]

Hi @reddrop it will work fine if i do lets say 3-5 at a time. some will fail but if i click retry eventually i will get all 5 to successfully set the startup disk.
i don't feel that trusting the server will fix this issue. i will look into it though.

regards
Pete