If your receive S/N is poor due to dish pointing misalignment then your transmit performance will be far worse, since the beamwidth from your dish at 30 GHz (transmit frequency) is much narrower than at 20 GHz (receive frequency).
So when it comes to dish pointing you need to adjust to the exact centre of the receive pattern. This position is not obvious, as the top of the beam is rounded. It may help to move off a little in each direction and physically half the distance measurement between exactly equally degraded signals at either side. It takes time and skill to do this but the result is larger clear sky link margins and less outage time due to severe rain.
Check that the outlink carrier is stable in level and not varying due to rain at the uplink teleport gateway site. Find out your beam number and gateway. I know some, and these shown if you move your mouse to your beam centre on this map:
https://www.satsig.net/tooway/satellite-dish-pointing-ka-sat-tooway-europe.htmGo to some weather web site to see current rainfall radar maps or weather-cam at your teleport gateway site.
Other reason for slow speed: Congestion.
I suggest you download and keep a copy of this recent document:
https://www.accesointernetsatelital.com/Data_speed_congestions.pdf for more detail.
They are presently saying that, due to congestion in some beams, users should expect 1 Mbit/s up and 5 Mbit/s down, on average, over 24 hours.
The fundamental problem is that each beam only has 400 Mbit/s capacity and, with several thousand (possibly rising eventually to 12000 ?) sites per beam, congestion is inevitable when everyone has unduly high expectations of both bit rate (20 Mbit/s)and Gbytes downloaded.
My advice would be to minimise your usage during peak periods (5pm-11pm weekdays), avoid streaming video and other high demand applications and to keeping your expectations moderate. You are sharing a limited amount of capacity with many other users.
Sales people need to make it clear what the system can provide, emphasising that many other sites share the available capacity.