Two issues with my BSNL FTTH connection


I am on BSNL 750 GB FTTH Plan and have two problems with the connection :-

1> I am not able to redial back to BSNL PPPoE from my Router.
I have disconnected from BSNL ONU, removed the credentials from it, and plugged the WAN cable of router to the 3rd port (Bridge port) of BSNL Nokia Siemens ONU.
After that, I setup a PPPoE connection in my TP-Link router and entered BSNL credentials.. in the first try it didnt connect.. I left it for almost 10 to 15 mins.. then I changed some random settings here and there in router, and it got connected. Again when router went off and back on, 20 minutes passed and it didnt connected.. took me again 1 hour fiddling with cables, router settings to make a successful redial to BSNL.
I am wanting to dial the PPPoE connection from my router instead of the ISP provided ONU because the ONU gives me max 60 to 70 Mbps DL Speed and 90 Mbps UL speed, but when dialling from Router, I get 93 Mbps DL and 90 to 95 Mbps UL speed, with 30ms ping less than ONU. Also, connecting from ONU gives extremely slow DL speed on wifi from my router.
Does anyone have a guess why my router randomly is able to dial the PPPoE and most of the time gives an error ?

2.> Since few days, I am not able to play many online games.. GTA 5, Red Dead Redemption 2, Battlefield V, Asphalt 9, Asphalt 8 etc. Origin login is not working, it says "online login is not available", and in GTA 5, it says "Rockstar Services are not available", even though I am able to play all these games with other internet. I tried disabling firewall, turning off SPI Firewall in router, bridging modem as above, but nothing helped. Steam Games, and other MMO RPG games which I play are working fine. Any idea how to resolve this ? I spoke already with the ISP and he asked me for the web addresses of the games affected, I sent him the links and he said he will look into this but until now, nothing happened.