I had the same issue with Avast VPN. I have tried your VPN twice in the last few years, on two different computers, one with Win 7 & 4GB memory,
the other on Win 10, with 8GB memory. Each time the speed of everything went down by a huge noticeable percentage, like 90% slower. Each time the speed reminded me of the 1990's with 56K dial-up. So, twice I uninstalled and cancelled, and Support could not help. This is a problem with the Avast VPN, and has nothing to do with the speed of the Internet Provider, and it happens at all times, even when local loads on a network ought to be at a minimum both at the country were one is, and the country one wishes to browse in.
Surely, around 5pm to 7pm local time, a lot of people come home from work and checks their e-mail, and one can experience a locally observable slowdown. But, when it's 11pm in the US, and 5am in the UK, then loads have decreased in the US, and have not yet increased in the UK. BY this logic, the VPN speed ought to speed up, but that's not observed. That's why I have asked Avast numerous times to re-engineer their VPN, but it seems "they don't want to".
One could imagine a VPN that is able to measure it's own achieved speed, and would provide usable answers as to what the cause may be, or even would reconfigure itself to the best available status. But that's not what Avast VPN can do. We are all dancing in the dark.
