It’s been going this since I have change the last contract with yours and 4G it’s only 3G! Hope you can help on this one! At least you’re not hanging up on me like most of yours tel. Advisors and please please please fix this because I’m not paying more than £100 for kinda fake stuff!!!!
The screen shot shows the speed to the hub as a little down but well within VM's minimum guarantee, the speed to your phone is over wifi and that looks about what I would expect you to get (the hub isn't wifi6 so c. 500 Mb/s is normal).
As for speeds over 4G, that's entirely down to local mast conditions and how many others are on it.
500 Mb/s to your phone is as fast as it's likely to get - the limiting factor here is how fast the wifi on the phone is. It doesn't matter how quick the raw internet connection is, the phone will never be any faster.