Hi, @RyBo3
Thank you for posting in Microsoft Q&A forum.
I guess this may be because you have configured the domain join information in customsettings.ini before, even you removed it now, but you are using the old boot image.
So you may try to update your deployment share to regenerate the boot image to see if it helps.
If you are using WDS, you may need to update it in your WDS server too.
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