Netduma Fraser

Could you uninstall the app, restart the phone, install the app - but don't open it, restart the phone then try again please?

What iOS version are you currently on? Could you provide a video of what you're seeing? Also verify in settings it's on the correct app version

Yes a MTU mismatch could cause it, glad to hear you found the cause

If they're directly after the issue happens and before a reboot then yes. Do you get the same issue with the PC connected directly to the ONT?

Make the issue happen and then grab the logs please. Also if you connect via ethernet to the ONT do you get the same issue?

So if you connect via WiFi instead to the router rather than the hotspot does it work?

Thank you, have you tried the following, if not please do so: Clear cache for Battle.net: https://www.youtube.com/watch?v=9Qx6kSeH2Jg Uninstall then reinstall Battle.net You're using WiFi on the PC to the R3 right - have you split the WiFi bands, if so which are you connecting to 2.4GHz or 5GHz? If you haven't, split them then try each band to see if there is a difference. Are you able to test via ethernet to the router?

I think setting QoS policies on the PC is more likely to confuse matters, I would revert that so we can know it's not affecting it whatsoever. Then what error specifically are you getting when going onto Battle.net/the game with Geo-Filter & SmartBOOST fully disabled?

It's better to get a summary from you of what happened for example - you did this how? "Removed endpoint DSCP marking" Disable SmartBOOST fully from the menu, does it work then?

Disabling DHCP prevents the router from dynamically providing IPs to devices - you should only ever disable DHCP if you have given devices static/reserved IPs either on the router or the device itself. It is likely that when the DHCP lease tried to renew that is when the issue became known. You do not need to disable DHCP for any performance gains.

The longer the cable the more subject to interference it is but it's usually fine up to ~100 meters. However with such a long cable it is much harder to determine if there are any kinks or internal breaks for example

Do you get the same issue on another device? Are you saying you changed the ethernet cable to a new one because you were having the issue?

It is on the Geo-Filter as Arc Raiders / The Finals. I haven't tested it personally but give it a try!

Added

Have you rebooted the router since the new speeds? If not, reboot from the interface, close the interface, wait 4 minutes then access, do you get the issue again? Do you get the issue on other devices if you test with those?