Jitter Test Online Gaming

I notice that if I run the Cloudflare jitter test my connection only gets an "Average" rating when not using a VPN, however if I perform the same test using Windscribe VPN via Manchester I get a "Great" rating.

Ping (without a VPN) has the lowest value when selecting Manchester TNP speedtest.net server so presume Virgin Media route my connection via Manchester - thus my rational for choosing Manchester for the VPN test.

I am curious how come the jitter is so much poorer when not using a VPN?I notice the same effect on my works VPN too.

I get Good for all three.

Via a VPN gives Average for Gaming though.

Jitter 3.9ms
Ping 13.1ms

Looks like time of day might also impact. Just tried now without VPN and get “great” for all.

Latency
19.5
ms

34.0
ms

33.5
ms

Jitter
4.58
ms

20.0
ms

7.47
ms

Packet Loss
0
%

Great for all three here.

Test ran at 8.30pm.

Jitter 2.84ms
Latency 14.5ms