Disconnects + pingspikes after 8.6

I have never had random disconnects since after 8.6. My ping is around 30 or 40 usually throughout the game, but randomly in-game I'd just disconnect for like 5-7 seconds, and it's frustrating to deal with.. I usually have to encounter these things once or twice a game

Here is everything I tried to do:

1. Restart modem
2. I'm already using ethernet
3. Disabling firewall
4. Disabling IP helper
5. Use hextech repair tool to repatch
6. Reinstall game entirely
7. Change DNS servers
8. Forward ports to league's servers
9. Not use a 3rd party tool like wtfast
10. Disable auto-replay thingy
11. Play on low traffic time periods
12. Update any network device via device manager
13. Remove any unnecessary background processes

And I'm still having these issues. My internet runs perfectly fine on other games without any lag besides league, and my ping in general is decent too. What do I do?