How to find the problem when copying online?

Question

System administration

The following situation began to be often reproduced:
There is vin10, there is a network sphere on synology, access to the folder through smb. Previously, I did not notice problems when copying from balls to a PC, but now copying has begun to "hang" in anticipation. When there are a lot of files in a folder, then when you try to copy, the destination folder freezes, as if copying is in progress. And the source folder works fine. Moreover, if I open the manager, I see that the network is loading but the folder is empty. If there are not many files in the folder, then it takes a minute, after a minute the folder hangs and copying starts.
The feeling is as if the files are first copied to some kind of buffer and placed there for quite some time, and after that copying to the local disk already begins.
How to check why this began to happen and how to remove such freezes?

Answer 1

If nothing has been updated, then you can check the disks for health.

Answer 2

and what about synology monitoring at this moment? what about free space?