https call with "access-token" header hangs indefinitely

I have a simple https get request with access-token embedded in the header. After calling requests.get(url, headers) call is not returning/timing out. I am calling backend services in url. Postman or curl all work fine but its only problem with chalice. Has someone faced this issue? I even try to see any packets sent by sniffing packets on wireshark..but it is not.

Other calls google news feed works fine in chalice, but these urls don't need any headers.

requestheaders = {"acess-token":"abcdef-123"}
holdingsUrl = 'https://api.dhan.co/holdings'
r = requests.get(holdingsUrl,headers=requestheaders). # call is not returning after this howerver other urls works fine

Start by reproducing the reported requests.get call in Chalice with the access-token header and the api.dhan.co/holdings URL, then compare it with the working Google News, curl, and Postman requests. Done means the cause of the indefinite hang is identified and the call either returns or has a documented, reproducible limitation.

Written by the indexing model from the issue text.