My Cloud sometimes refuses to connect


We have purchased a My Cloud device recently and we are using it so some of our clients can access and download their data after a big session. (Talking about around 50GB transfer in average).
We have enabled remote access and ftp access and everything works fine. But sometimes out of the blue clients can’t connect, and the cloud is not accessible. After a while it continues working as nothing has happened. It’s really frustrating because we bought it solely for this purpose, so the clients can access their files anytime.
The cloud is connected trough a timecapsule router and has static ip address.
Can this be resolved?

Thanks in advance,

Which My Cloud device do you have? Does it look like this?

If it does then see the following information for more help.

How many clients do you have that are trying to connect at the same time?