We have a small marketing firm, and we use the Unattended access to remotely install updates and roll out new items when our employees are gone in the evenings. 

Everything has been working fine, until the most recent update to the Zoho Assist. It shows all computers are offline. 

We have removed them and had them reinstall the new download package, they will then popup in my Unattended Access list, but it still shows them as off line. I wanted to see if there was something that we are missing as a part of this equation. We did recently install a new Dlink router in the office, so i am not sure if there is any setting that might need to be adjusted within the router that is stopping traffic or something. I am not an IT guru by any means. 

All of our systems are on OS 10.14, and we did make sure to grant access under the Security and Privacy settings on each system. Any help would be appreciated.