DNS Leak due to ISP forcing

Hi, having an issue with a dns leak. Using the mt300n, openvpn installed. VPN provider has given me their dns servers, I added them manually, and still leaking. VPN support have advised the ISP I’m using (I’m at an airbnb so have no control over ISP choice) is forcing a dns lookup. Any way to fix this as it’s crippling my speeds up and down to the point of unusable?

Can you turn on DNS via TLS Cloudflare or other encrypted DNS proxies?

The VPN service provider’s DNS servers should be set automatically by their DHCP without having to enter them manually.

Th

This should be the default action for openvpn in stock firmware.