Looking for Help - Ping Spikes in Fights

After this TFT update, around stage 4, I will start getting ramping-up ping in fights (sometimes it oges back to normal after the round is finished). It gets so bad I have to restart the game after every fight in order to be able to use shop.
Everything else works fine, no lag, no ping issue, no connection error.
Just TFT.
I ended up submiting the ticket, but no IPv4 tweak or Riot repair tool helped.
Any idea?