Started with Virgin in December on the m100 package when I moved into a new house (Leamington Spa) and my download speed when testing online is never above 22-23mbps.
I lag a lot when I game, games such as rocket league where ping used to be 26 is now averaging around 76 making it really difficult to play online. My girlfriend has similar experiences in that she cannot connect to her family over skype without horrible lag. If someone watches netflix while I try to game it gets even worse.
I do not use a wired connection to gaming console and never have in my life whilst in my previous home so would prefer to keep everything wireless - with the same M100 package I would have great connection whilst most nights I would have my father gaming on his computer/watching videos online, my sister watching netflix upstairs and my mum watching netflix in the living room all whilst I would be playing online with friends without any lag or poor connection (this was also completely wireless). For this reason I think something may be wrong as I have never had issues previously with this Virgin package.
I am not the most tech savvy person so if anyone is kind enough to take the time to reply, please do feel free to talk in simple terms!
Unfortunately you will not get the best performance from WiFi connections, and WiFi speeds are not guaranteed. There are ways of improving WiFi performance, but before working on that and possibly having to spend money you need to establish whether this is a broadband problem. Can you connect your games box by ethernet to see if it works properly that way?