Can't undo purchases all the time.

I'm pretty sure we've all experienced the bug. I've dealt with it probably around 100 times total and it's been around for months (over a year I believe). The cause is something to do with the sequence of purchases or something. I remember it happened twice in one Lissandra game the other day. I ended up with MR boots and a warmog's that I didn't want.

Another thought I had is maybe it has something to do with leaving the centre of the fountain (walking on the stairs of spawn). Might also just be red/blue side spawn (I think it's red but not sure I play on blue team every game because of settings). I always remember it happening on red side for some reason but that might just be the recent times.