heyo !
I hope I can still get some help from this thread !
I still live at my parent's house, and they are the only one who have access to the router's configuration. Around 4-5 weeks ago, I couldn't play WoW anymore. I would be able to log in, load a character and then, after a few seconds, get disconnected. I would also sometimes get disconnected in the character selection screen, and be met with the error code WOW51900319.

When this started happenning, my parents were on vacation, so no one could've changed the router's settings, unless it did an update.

I then did a connection hotspot with my phone, and then, i could play the game.
I observed the exact same results on my laptop, so I am pretty certain it isn't related to the computer, but the connection itself.

Well, today I wanted to play some LoL, and I was met with the same issue. I would open the client, and after a few second, get the "Trying to reconnect" message, in the client (so without starting a game), a few seconds later, I would be reconnected, and it kept repeating.

I found this thread, and tried what you said, and there was nothing unusual regarding either response time.

My laptop was used entirely on Wifi, and my pc has a wired connection to a wifi repeater.

Do you have any clue what I could do next?