Have you run "sudo jamf recon" on them? Devices should check in every 15 minutes and do a full poll weekly unless you have a workflow to make it happen more frequently. 

Unless someone deletes it, a Jamf Pro server will have a policy that runs an inventory daily. Do you have that policy? If not, you should create it and scope it to all of your computers. Do these Macs show any updated information such as new app installs and other data that an inventory would collect?

@AJPinto 

i did a sudo jamf recon script set to weekly 

@howie_isaacks 

think that is what happened will have to looking to creating a new one