Also consider what is between you and the router. Distance is only one factor. I’m running an eero mesh connected to my ISP box. One of the eeros is in one room, but depending on where I am in the next room, maybe ~10ft away, I get a spotty connection. On the flip side, other places in the house or even outside, 50ft away are fine. Though I can’t be certain, my guess is the closet between the two rooms is blocking a lot of the signal, which probably is made worse by the closet having floor-to-ceiling sliding mirror doors spanning most of the wall. I’m planning to move the eero to a different position to see if that helps avoid the closet interference.
So perhaps try moving the router, if possible. You can also try using mobile apps like “Oka Wifi” to map out signal strength in various locations to identify dead spots.