If your speed drops at peak times it's because the service is oversubscribed in your area and there's not enough bandwidth to meet the demand. You're not being traffic managed, the service just can't support the number of users.
Welcome to the community. It's nice to have you here.
I'm sorry to read that you are experiencing slow broadband speeds during the evenings.
I've managed to locate your account and there is a high peak time traffic fault in your area which is causing these slow speeds. Our networks team are investigating the problem and are improving bandwidth and performance to help with this issue. The reference number is F004862937 and with a review date of 21st December.
I will pass this across to one of my colleagues who will be in touch with more information.
Apologies that there was not a reply to the message you sent.
In regards to the issue you brought to our attention, you would need to contact our Customer Services department on either 150 free from a Virgin Media Landline or 0345 454 1111 to discuss this further.