Slow speed on booster even when wired?

[wireless]

Hello... I hope I’m able to find a solution here for my problem with the experienced members. I have this weird spot in my basement that I’m unable to get my Telus Booster to maintain acceptable speed. I have Cat6 cable though the house, and I have an outlet in the room next to this one weird area (it’s a studio suite, separated by one interior door). In that basement I have a wall outlet for 1Gbps connection. I’ve tested it with my laptop and I can achieve avg of 750mbps connection. From here, I hardwired with a Cat6 patch cable to a Telus Booster placed on the other side of the door in the studio suite, but I just cannot manage to get the wifi speed past 40mbps. I have 2 other boosters upstairs that’s also wired, both gives me avg 250mbps on wifi. I’ve done a factory reset of the basement booster and made no differences. I’ve switch out known fast boosters from upstairs and place it downstairs and same slow result. What am I doing wrong???

More... (https://forum.telus.com/t5/Internet-Home-Phone/Slow-speed-on-booster-even-when-wired/m-p/117566#M28917)