Please tell me I am not going crazy: Is League of Legends client causing me connection problems?

So lately when I play League of Legends I get lag spikes here and there, something that never happened to me before, is not only at my place tho, when I go to a "gaming café" or however you call it, I get problems with my ping too.

Anyway, so I'm sitting there trying to play a match in my sister's account. The connection problem is so high, I decide to leave the game (I'm sorry, but I really couldn't even move), I noticed that my phone was also having connection problems, at that moment I leave League's client on in the background while I try to restart my phone and get a snack, then just by curiosity I close the game's client and, no joke instantly everything goes back to normal? Wi-Fi's back on my phone, I have good connection in my computer once again??? It's just weird af

Please tell me I'm not trippin', and hopefully this happened to someone else out there that can just tell me what the hell is this all about?