After a json_warning in api.Requests, the protocol assignment switches the scheme in _http_request due to T326046. In some cases this results in HTTP 403 responses (again with json_warning), because the selected scheme is incorrect. The bot then keeps using the wrong scheme until a Timeout exception occurs.
The html message contains this:
Wikimedia Error Error Insecure request forbidden, use HTTPS instead. For details see https://lists.wikimedia.org/hyperkitty/list/mediawiki-api-announce@lists.wikimedia.org/message/VKQJRS36NXLIMHOWBOXJPUH35KETQCG5/.