I have a Archer GX90 triband router it provides good pretty good coverage and speed on all of my Wifi6,5 and wired devices. i thought adding a Wifi 6 one mesh extender would compliment the router as devices increase and in some far away spots.i just bought RE700x wifi 6 extender and configured with the GX90 router ane enabled one mesh.

to my surprise the performance drops when this RE700x is powered on. Down speeds dropped almost to half . when i power of RE700x the devices connect to router and the down speeds are higher. just got this couple of days ago and was such a disappointment.While i was so impressed with the GX90 i got this and wanted to simply wifi with a one mesh but then my speeds dropped. not to mention non wifi6 devices like wifi 5 or 4 devices are even worse. specifically 2.4 Mhz is terrible.

setup is straight forward and the location of extender per the Thether app is in a good spot. what i am doing worng could you suggest?