[GAMEPLAY] Inability to control character (repeated, short spurts of time)

Since 5.17 was released I've been having this issue. Every so often (usually every 20 - 60s) I'll have about 2 seconds where no commands go through, and then at the end of the 2 second interval, all of the commands register at once. This happens every single game, without fail, throughout the entire game.

Possibilities Ruled Out: (1) Packet Loss/ISP issue: My first thought was an ISP issue so I started asking around at my university. No one else has had this problem. My room mate, who sits 10 feet from me and plays on the same model of computer doesn't have the issue. Furthermore, there is no ping spike registered. (2) Hardware issue: This is possible, but unlikely seeing as I had no issue before 5.17. I've tried different mice of all kinds, and I've never noticed the effect outside of the client. (3) Client issue: I've reinstalled the client several times since 5.17 was released and each time I have the same issue. Given the fact that none of my other league buddies are reporting the same issue, I doubt it's a client-side issue.

Example: I was playing Vel'Koz the other day against a Leblanc mid and Rengar top, both champions that require precise timing. I went to gank top lane at one point and rengar ulted me. I prepared my fingers when I saw the exclamation. He jumped on me and I started mashing buttons on top of him but nothing happened. Just before I died, all of my skillshots fired away from him, as I was frantically clicking away from him without moving.