Thanks for you reply!
I've opened ticket with HE but since I've noticed exactly same issue with different (non HE) tunnel server I doubted HE will find anything.
Are you using cCable as well?
In what area approximately are you located?
What sort of ping time do you have to google.com with ipv4 and ipv6? Are they different?
I'm located in Oakville. I have 15ms ping to google over ipv4 and in fluctuates by couple of ms. Over ipv6 I get 50ms and it fluctuates a lot - I often see as much as 100ms, some times I see 20ms.
I do not think it is a setup issue - I have been using same router/config for several years now. And I do not really see how router's setup can affect anything in the evening and work fine in the morning
. All measurements done without any other internet usage.
Thanks again!