Which exit point are you using? How close is it to you? I only get about 5MBps no matter which node I use and have suspected ISP throttling, but haven't tested too much since 5MBps is enough to get by with; this might make a good way to gather more info.
With Surfshark, an assortment of (mostly) European locations - e.g. Germany, Netherlands, Czech Republic, Switzerland. When things were slow, the choice of exit location didn't seem to make much difference - tho' sometimes I needed to cycle through to find one that worked at all.
With Mullvad, a similar choice of locations - again, it doesn't seem to matter, but in a good way.
