Does using a vpn interrupts python sessions requests which are using the same cookies over and over?
HTTP 400 is returned, if the request is malformed.
You should inspect the request being made, when you get the error. Perhaps, it is not properly encoded. 
VPN should not cause an HTTP 400.
I am scraping data from peoplefinders.com a website which is not accesible from my home country so I am basically using a vpn client. 
I login to this website with a session post and through the same session I get items from different pages of the same website. The problem is that I do scraping in a for loop with get requests but for some reason I receive response 400 error after a several iterations. The error occurs after scraping 4-5 pages on average. 
Is it due to fact that I am using a vpn connection ?
Doesn't all requests from the same session contains same cookies and hence allow me to keep logged in while scraping different pages of the same website ?
Thank You