Remote connection problem to 3TB mycloud

For my 3TB mycloud, I have made all the required adjustment and made it running ok for remote and local connection. It run a few days ok. Then it started to give problems for remote connection. It happened five times in two months. I couldn t connect it remotely. I have found the solution by trial and error: From the dashboard when  I restart the mycloud,  I can access it remotely. It is ok for a few days then  It occurs again. How I can solve this problem permenantly. Could you please help me?