Steam and the recently played games jump list

This sounds like the file storing that information got corrupted.

• First, open the following folder in Windows Explorer:
  %AppData%\Microsoft\Windows\Recent\CustomDestinations
• Start Steam, wait for it to load, then close it again.
• Now check the folder you've opened before. There should be one file that's been modified right now. In my case, the file name is 493e32cec2810e2e.customDestinations-ms, but you might have a different one.
• Move it to your Recycle Bin or another folder. This way you're able to restore it, in case something breaks.
• Restart Steam.
• If everything worked, your jump list should be back and building once again.

in steam go to settings, then interface... from here click on set task bar menu. The problem is there's too many options in your jump list, de-select a few and bingo more "recently played games" will appear

This may not fix your problem, since you say it's always displaying at least one Recent item, but I ran into an issue where the Steam jump list never displayed any Recent items at all, and discovered that the option to store and display recent items had been turned off globally.

To check this option, right click the task bar and select Properties. On the Start Menu tab, make sure the "Store and display recently opened items in the Start menu and the taskbar" option is checked.