CSP Gateway | Error Condition: Failed to read posted content from the client

Hello experts,

I'm new to InterSystems software and still not so familiar with it. Therefore I do apologize in front if this question is irrelevant, not making sense or answer is commonly known.
 

I've did my best in search for answer, but unfortunately i haven't found anything helpfull. So I decided to ask for help here.

My problem is repetitive error which occure in CSP Gateway event log : 

Error Condition: Failed to read posted content from the client (Content-Length: 1404; Data Actually Read: 0; Read Error: 70007)

It occure approximately 40 times a day. Customers do not report any specific problems, but it's still in my concern to solve errors.

I was looking for explanation of error in various documentations : 
https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=GCGI_oper_config

https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=GCSP_ErrorNotes

internal CSP gatewat Help
 

Also google error message

However my search was not successful. 

Can any of you experts explain to me what is causing this error ? Is it server side problem ? Should I be worried ? 

Thank you in advance for any advice or hint.