Region : Others

Model : TL-WR340G

Hardware Version : V5

Firmware Version : 4.5.0

ISP :

Greetings

Recently i switched ISPs to get decent speeds and i bumped into a really weird problem.

When i connect one of the PCs directly to the cable coming from the EPON ONU i get my normal speeds (70-90 Mbps), but after i introduce the router and connect my 2 PCs to it my speed can not go past 10 Mbps on any of them.
What confused me was that i found a way to temporarily fix the problem by letting the router aquire IP and other needed information from the Network (i am using Dynamic IP), after it does that i would take the Cable from the EPON - plug it into the PC directly and wait for it to aquire the IP. After that i return the cable back into the router's WAN port and for some reason now i get full speeds behind the router on both my PCs. And that does not make any sense to me.
That lasts until the router reboots for some reason (power outage, change of settings etc). After a router reboot the problem is back and i have to do the whole cable swapping ritual again.

I can't figure out what could be the cause of that.
Is the router just giving way or it is some sort of miscomunication between it and the ONU.

Any help is appreciated.

Regards