@nightranger 

Hi,

5 to 7 m is actually not that far away. 
Do both, the router and the PC, have adjustable antennas? 
If yes, have you already tried to maximize the signal by adjusting the direction of the antennas?

Besides the signal being low, how is the actual data throughput speed between router and PC?

The thing with range extenders is that due to the way they work the attainable speed through the wireless extender will only be about half the speed that can be achieved via a direct wireless connection between router and client device. (assuming similar signal levels)

Therefore, in some cases a low signal direct wireless connection between the router and the client device can still result in a faster data speed than a strong signal connection through a range extender.

As far as TP-Link's Wi-Fi 6 802.11ax range extenders are concerned, I doubt there is much difference (if any) in signal strength between them. After all, the all have to comply with the local government regulations and can't exceed the imposed limits.
https://www.tp-link.com/en/home-networking/range-extender/?filterby=5730
 

  @nightranger 

Hi,

The distance of 5-7 meters is not very far, the signal is too poor may be because the material of the floor cuts the signal too much, for this case, it is recommended that you use powerline adapter,such as PG2400P KIT and TP-WPA8631P KIT