Are you able to test a different windows 10 client. If it works from windows server it doesn’t sound like the problem with with the Isilon. 
Hi Dell support,   Our ISILON L400 cannot transfer files and keeps prompting Error 0x8007003B. All our users receiving this error. How to resolve this issue. Our shared folder (SMB) is not fully consumed and has a lot of free space. [IMAGE] We need your help! Thank you! Je- M    
Isilon encountered error (0x8007003B: An unexpected network error occurred)