Yes! I have the same problem. This is horrible!
IIf you change the hosting I have high ping in the evenings.
I think that the fault of the hosting company.
Any security or limit for people with variable ip
"Orange" internet provides Poland with a variable IP, this company is a monopolist in telecommunications
As Orange is a French firm, I can tell you that they have many customers there, and as far as I know 70 to 80% of those users are experiencing this issue with the ping. It couldn't be the server's hosting society but the ISP only , I have another French ISP , and I got a 2 times (50-->25) better ping, since they set up the servers with that new host.
Orange is responsible of this sh*t and as it affects only a minority of customers I think that they won't change anything, I had orange as an ISP before and I can assert you that those guys are some lazy dic*s in France... Can't even imagine in Poland.
Nevertheless as a hopeless solution, I can recommend to try the fast path mode with your Internet line , that helped me out sometimes with orange , but still it was efficient in a few games only, and yet I don't know if it stills fee-less to do that with orange , they might ask some money for it :p.
And if you think that your problem is linked to the variable IPs That Orange provides, then ask them for a static one, I know that it's possible with them, however here it costs 3€/month .