That's better, it does not look to be too bad, however, every device can be different, different antenna, case or location.
A different router/hub might improve it, it might make it worse! Most will aim for the maximum legal power. Try turning the original through 45, 90, 135 degrees and see if the signal strength changes - with some it may.
You would want one with LAN ports - WAN is the Internet, LAN is your house.
The simplest and easiest way would be cable and a WAP - not your preference but little else you could easily do. There are some fairly thin Cat5e cables - and if you can conceal that, then problem solved. Can you access under the floor?
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