Nobody here except you knows what service you run on port 7006... What is it? Node.js? Proxy server?
7006 port is not managed by any service of Directadmin. So you must have something different from most of, something that you installed your own. Since that we don't know how you managed to install a cert into this service and we don't know how to renew a cert for your custom service. All possible solutions were already suggested.
Whatever it might be you should make sure that it reads a cert from a place where directadmin installs it and make sure it restarted after a cert renewal.
Without knowing details there is hardly anybody else here who would like to play a guess-game. So please provide more details if you want a further assistance or hire somebody to check and fix it for you.
Thanks for the reply
If we have a node.js running on that port, we made the creation of ssl certificates using directadmin and worked fine, then it could be renewed, except as I mention on port 7006.
Is there any guide how to check the cert please?
Sorry for not knowing
Whatever it might be you should make sure that it reads a cert from a place where directadmin installs it and make sure it restarted after a cert renewal.