I have the same experience. I alternate between servers because the speed will drop overtime. Using wireguard protocol, I’m unsure if it’s mullvad or my ISP.
Because ISPs like to take much money for slow speed, I’m paying +40€/mo for 100mbps down, 6mbps up. No, I didn’t forget a zero.
Set your MTU to 1420. Change your port from Automatic (usually defaults to 53 DNS) and set it to 51820. Disable Obfuscation, Quantum Resistant tunnel and DAITA. I had similar issues due to DNS port use conflicting with other settings. I am now getting 12ms latency and full line speed on gigabit using an ASUS GT-BE98.
Hmm, i’ve been using ashburn
My guess it’s Mullvad since I don’t experience any speed drops without Mullvad.