VPN prevents some pages from opening or slows them down significantly. That’s why it’s always switched off on my computer.Therefore no recommendation!
First, I’m an Avast user and not an Avast Team member and I don’t use a VPN.
However there is going to be an overhead with the routing of your request and the return, some sites actively try to prevent VPN, security/restricted content, etc.
You can try using split tunnelling (not even sure if this is available on the Avast SecureLine VPN or not.
This is a search on using split tunnelling,
And