Disconnection issues, but only with league

So, this may sound like the typical 'blame riot for connection' thread, but hear me out. For the first 52ish minutes of the game, everything was normal. I had 200 ping, the usual amount I get from playing from Korea on the North American Server. (Because I can't read Korean)

At the 56th minute 10 seconds before respawning from a death, my ping spiked up to 2887 ms (or somewhere around 2800), and the usual disconnection loading box popped up. I could not do anything, including switching off the clash speaking to attempt to lower the ping. After ~ 5 seconds, I decided to quit the game and rejoin from the client. Here's the weird part. I could hear really laggy voices from my teammates. I also infer that they couldn't hear me yell 'LAAAAAAAG', as there was no response. When I switch off the voice from the client, my friend list disappears and there was a poro saying 'It appears you are offline' or something along those lines, as well as the fact that I could not rejoin the game. I closed league using task manager and started again, resulting in the client needing some update. After updating, the game was over, and that was the end of it. Or so I thought. My client (yes, client) occasionally disconnects and shows the poro message for around 2 seconds, and then turns back to normal. I would infer this as a sign that the lag is still there, and therefore would like to ask what I can do to prevent the lag spike and disconnect. I play with wifi, and my network was stable at the time. I am currently typing this with the client still on, and it just disconnected for two seconds again, but my browser shows no sign of disconnection. I think that there is a fair chance that it actually is my computer/network's problem, but I believe that the chance of it being a problem in the client is higher, as I do not experience lag/disconnects when using my browser, discord or when playing other games.

The champions in my game were tryndamere, rengar, cassiopeia, miss fortune, talon, quinn, hecarim, veigar, sivir and zillean. (So it's not some smite karthus/taliyah or mordekaiser bug)

I do not open any sort of software when playing league (apart from task manager when I have already disconnected), so it's not a problem caused by the new cheat-prevention systems recently added. (Or so I hope, maybe that was why the client occasionally disconnects)

I know that this sounds like bullcrap and that I should probably just play on the Korean Server, if I want stable connection but I'd like some answers on what the problem might possibly be.

PS: It was a normal game. No LP Lost :) However, I feel that my honor level has deteriorated from this disconnection/bug. PS (2) : I am unable to use a LAN wire as all slots for wires have been occupied by my roommates. (There's 6 of us)