Hi,
Having the same issue here I thought I should share my experience.
Test with my 1Gbs internet = around 1-4 Mbps (test id 4160)
Test with my phone (other provider) = 35 Mbps (test id 4159)
Not sure about the others but on my side its definitely my internet provider having low bandwith issues to your servers. (Orange = French internet provider).
Had the same issue with other servers in Germany and a "tracert" to your servers indicate it transit by the same I had issues with = *opentransit.net . (Nothing to do except waiting for an upgrade on my provider side.)
5 2 ms 2 ms 2 ms ae40-0.niidf101.Paris3eArrondissement.francetelecom.net [81.253.129.137]
6 2 ms 1 ms 3 ms 193.252.137.10
7 2 ms 1 ms 1 ms tatateleglobe-10.gw.opentransit.net [193.251.251.20]
8 12 ms 12 ms 12 ms if-ae-9-2.tcore2.fnm-frankfurt.as6453.net [195.219.87.9]
9 13 ms 12 ms 13 ms if-ae-59-2.tcore1.fr0-frankfurt.as6453.net [195.219.87.195]
10 15 ms 15 ms 21 ms 195.219.219.10
11 17 ms 18 ms 17 ms core22.fsn1.hetzner.com [213.239.245.17]
12 18 ms 17 ms 17 ms ex9k1.dc1.fsn1.hetzner.com [213.239.245.234]
13 17 ms 17 ms 17 ms fsn-de3-cdn.vrvideo.cloud [195.201.193.115]