@Virgo There is no possibility to connect directly gpon ont to Xbox - it's not supporting PPPoE connection. I will try to get some other router and try to reproduce this case. I tried to reproduce it...

After switching to ER707-M2 I'm experiencing strange situation during downloading huge (~30GB) updates for games, but only on Xbox Series X. Download using PS5, PC/MAC is not generating this...

I'm experiencing exactly the same issues on my EAP670 with fw 1.0.12. After downgrading to 1.0.6 everything is working normally.