Riven E will not cast until you cast another spell

I can't screenshot the problem nor do I have recording software, if video proof is needed, i will download obs or something and get a video recording of it and upload it on youtube and post it here.

In some instances while playing riven, My E will not cast until I cast another spell like q or w. I haven't tested out how long it stays like this if I dont use any other spells, but I once walked into lane unable to cast E. I have only noticed this when I come out of spawn. I don't think this happens randomly when your just in lane farming or something. Every time i catch this bug I only do so in spawn when I am trying to use my e for fun to get to lane. I think it only happens when you spawn from death, not when you go back to base using B.

The E's picture stays black like when you don't place a skill point into it, then when I use q, the color comes back and it lets me use it again. It happens more than once a game.

I haven't tried using my W to bring it back, but I think it might work just as it works when I press q, but someone should test that.

I dont know if this is just like my client or not since I don't see this in any bug report yet.