Ok narrowed down the cause. This is from Text3d.uplugin the plugin’s config for text 3d.
Notice the TargetDenyList Server.
It doesn’t pack by design as ui elements don’t exist on dedicated servers.
You could clone the plugin into your project and remove the deny list entry and in theory it would pack, but the question is why do you need ui elements on the server if there is no graphics there?
the pre processor
#if !UE_SERVER
// your code here
#endif // !UE_SERVER
can be used to strip elements on the server (notice the ! to negate the is server check)