Unnable to create presigned url to download object from eu-west-3 - amazon-web-services

Question

Im trying to create presigned urls to give download access to private files that live on an S3 bucket. I have 2 buckets, one on us-east-1 and the other on eu-west-3.
I've tried creating the presigned url with both AWS CLI and Python SDK (Boto 3) but didn't manage to get lucky when doing it on the EU bucket. On the us-east-1, i can do it with V2 and V4 signing.
The server always returns this response:
<Error>
<Code>SignatureDoesNotMatch</Code>
<Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>MYACCESSKEY</AWSAccessKeyId><StringToSign>AWS4-HMAC-SHA256
20190829T174117Z
20190829/eu-west-3/s3/aws4_request
e57ecda0a9ef1693b962d285c1748bd28284d2e2d069bceb44fad975e480b964</StringToSign><SignatureProvided>674e84fda296c6d0e14ff8dd6a02f9af92d08ed2f6556547c63cbd057603148f</SignatureProvided><StringToSignBytes></StringToSignBytes>
<CanonicalRequest>GET
/public/video.mp4
X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=MYACCESSKEY%2F20190829%2Feu-west-3%2Fs3%2Faws4_request&X-Amz-Date=20190829T174117Z&X-Amz-Expires=600&X-Amz-SignedHeaders=host
host:mybucket.s3.eu-west-3.amazonaws.com
host
UNSIGNED-PAYLOAD</CanonicalRequest>
<CanonicalRequestBytes>47 45 54 0a 2f 70 75 62 6c 69 63 2f 76 69 64 65 6f 2e 6d 70 34 0a 58 2d 41 6d 7a 2d 41 6c 67 6f 72 69 74 68 6d 3d 41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 26 58 2d 41 6d 7a 2d 43 72 65 64 65 6e 74 69 61 6c 3d 41 4b 49 41 5a 54 48 34 47 4b 4b 57 58 42 55 59 48 46 55 59 25 32 46 32 30 31 39 30 38 32 39 25 32 46 65 75 2d 77 65 73 74 2d 33 25 32 46 73 33 25 32 46 61 77 73 34 5f 72 65 71 75 65 73 74 26 58 2d 41 6d 7a 2d 44 61 74 65 3d 32 30 31 39 30 38 32 39 54 31 37 34 31 31 37 5a 26 58 2d 41 6d 7a 2d 45 78 70 69 72 65 73 3d 36 30 30 26 58 2d 41 6d 7a 2d 53 69 67 6e 65 64 48 65 61 64 65 72 73 3d 68 6f 73 74 0a 68 6f 73 74 3a 65 75 73 74 6f 72 65 2d 6d 6f 68 6f 2e 73 33 2e 65 75 2d 77 65 73 74 2d 33 2e 61 6d 61 7a 6f 6e 61 77 73 2e 63 6f 6d 0a 0a 68 6f 73 74 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes>
<RequestId>496495C76B32097B</RequestId>
<HostId>Eue5AWLgtRWvivCE9ralzfc1ilUrLsnT+bWakSbeR5JYoSk1vbhYpwFxbeDbozJ7f1X1KLA5+Zc=</HostId></Error>
I obscured the bucket name and access key.
Here it is my python code: I'm using boto3-1.9.218 botocore-1.12.218 and Python 2.7.13.
import logging
import boto3
from botocore.exceptions import ClientError
import requests
from botocore.client import Config
'''
region = 'us-east-1'
tbucket = '<usbucket>'
'''
region = 'eu-west-3'
tbucket = '<eubucket>'
filekey = 'public/video.mp4'
s3 = boto3.client(
's3',
# Hard coded strings as credentials, not recommended.
aws_access_key_id='<access_key_id>',
aws_secret_access_key='<secret>',
config=Config(signature_version='s3v4'),
region_name=region
)
# This works
response = s3.list_buckets()
print('Existing buckets:')
for bucket in response['Buckets']:
print(bucket["Name"])
# this works
s3.download_file(tbucket, filekey, 'some video.mp4')
# this works
url = ""
try:
url = s3.generate_presigned_url('get_object', Params={ 'Bucket': tbucket, 'Key': filekey }, ExpiresIn=600)
except ClientError as e:
logging.error(e)
# Using the url does not work. Error 403
print(url)
if url is not None:
response = requests.get(url)
print(response)