I've probably spent over 10 months total on the QM2 but haven't been back since 2019.
As far as I can remember, the internet was a problem in the last decade on the ship, especially in the rooms and hallways.
This was sometimes frustrating for me because I had to take care of some business emails and sometimes phone calls but the link quality was really bad.
Until I figured out that the problem was the WIFI, not the ship's internet. My mistake initially was thinking that the satellite connection is not good.
I don't know what the situation is now but up until 2019 the 'fix' was simple.
Go down to deck 2 front, where the computer classes are being taught. There is an area outside with drinks, desks, and chairs etc. In that area the WIFI is fantastic, super fast and reliable, and you can get all your work done quickly. Using the internet during dinner time helps getting better internet speeds.
It also makes sense to have outlook on your laptop so that you can receive and send all your emails in just a few minutes, instead of using a web email account.