My Cloud / many issues with speed using Mac version of MS Word

We are having huge problems with the speed of saving and opening files on My Cloud
It is especially MS Word from MacOS

All firmware, OS and MS Office are latest versions.

Even when only 1 person working with the NAS / Word document it takes forever

plenty of free space on the server.

ANY one having ideas of what to do?

the NAS is connected with cable to the Router
thanks in advance

What speed is your router and computers? 10/100 or 10/100/1000?

How are you opening and saving the files? Downloading and working on the documents on a computer or doing it all through the MyCloud?

You are not supplying enough information for anyone to give you help.

We are using WIFI 2.4G from the computers

We are working on the document directly - not uploading / downloading directly

the Server works as a network drive.

I will add this to what SectorGZ asked. Do you have 802.11ac wifi? If not, what do you have? What router do you have and its speed? Do you have a 5 GHz Channel or is your router only 2.4 GHz?

Thanks as mentioned the router is a 2.4GHz and yes it is 802.11ac