I don't know if this was reported before. However this is a small bug, not so important thing, but I just noticed it yesterday, so I just wanna report it here.
So, when you click at your Summoner profile and then go to your Champion list, at _Availability_ option you can chose:
4. Not Owned and
5. **Recently Purchased**
When you chose **Recently Purchased** it randomly shows champions. Yesterday it showed a few champions, but one of those were champions that I bought over 2 years ago. Today when I checked it showed another, different, champions. So that thing is not working properly like other options.
I recently bought Maokai (which is correct, but it wasn't included yesterday as well when I checked thist list for the 1st time), Sion, Shyvana, Bard, Graves, etc. I bought Soraka, Evelynn and LeBlanc a long time ago.