Google through proxy through Python?

Question

Python

Python script, super simple

import logging
logging.basicConfig(level=logging.DEBUG)

from grab import Grab
from pprint import pprint

g = Grab()g.setup(   connect_timeout=10,   timeout=10,   proxy="142.193.116.100:7738",
   proxy_type='socks5',
   user_agent='Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36'
)

url = 'https://www.google.com/'
g.go(url)
print(g.doc.url)
pprint(g.doc.body)

Google gives a 400 error through a proxy, but other sites work.
If you insert a proxy in the browser, then everything is ok, everything is ok through the curl too.
Checked with a user agent from a python, it also does not enter.
Where could the problem be?