Connection stability issues

I tried everything i could to figure out the issue, my router says everythings completely fine but my ps5 keeps constantly dropping my internet connection nonstop. I have a wifi extender thats better than the xfinity xpods and im using it and it says the connections good/stable. I keep consistantly disconnecting and the modem/router is on the first floor but im in the attic, i tried moving the extender to the second floor and it barely helped either i keep getting the same results, i tried changing frequencieson both the console and the extender. It seems to be that ever since i upgraded to the new modem that the range is just god awful compared to the previous router i had and i feel like i shouldnt even be paying for a said service that i can hardly even use or enjoy. 

I tried everything i could but i cannot move the modem/routers location either due to not having any coaxial cable entrances.