EasyMesh isn't easy, EasyMesh Vs AP
I have an Archer AX10 as my main router, and an Archer AX23 set up as a subnet with a different SSID, in another room which is quite far away. They both work very well for months.
However, when you move from AX23 and somewhere close to AX10 (and vice versa), your phone will still tries to use the connected one that's further away, with a degraded speed. To improve speed, I have to switch manually.
EasyMesh comes for the rescue, I thought.
I log into AX23 and at EasyMesh change it from the main router into a satellite router.
Then at AX10, which is already a main router, I click add satellite router. It started the scanning. for 10 minute or so, and never come back. I try reload the setup page, it was not responding. I end up turn it off and on again. All AX10's setting got wiped out. When I load the setup page, it asks for set up admin password or so. Like it was factory reset and ask me to setup admin password. I have to enter all my settings again.
Q1 Did I do it wrong?
As it is my working environment, I didn't try it again for EasyMesh.
I end up setting AX23 into AP mode, and setup its WIFI having the same SSID/PW as AX10.
To avoid collision, I change the channel from auto into something different for each router.
It seems to work out well, I walk to and fro with my phone connected to the internet playing some video and no interruptions.
Q2: is my setting 2nd router as AP a good idea? Any pitfall?
Q3: I guess Meshing is doing something similar?
The "add Satellite" feature of the main router's (AX10) web interface can only add a Satellite by finding it via Wi-Fi first. Therefore, if the router that is to become the Satellite is too far away to be found, then obviously that can't work.
If you want to add the AX23 as a Satellite directly via a wired connection, then you need to use a different method, which is:
1) Either reset the AX23 to factory default settings (for "easi(mesh)ness" 
you can just press and hold the physical "Reset" button) or switch it to "Satellite Mode" via the web interface. (both ultimately result in the same thing and yes, this also deletes the admin password)
2) Wait 2 to 3 minutes until the AX23 has booted up again, but do not create a new login password on the AX23.
3) Plug the Ethernet cable that comes from the AX10 into one of the LAN ports of the AX23. -> This should initiate the process of adding the AX23 as EasyMesh Satellite. You should notice that the LEDs of the AX23 then behave in a pattern like you usually see when you power up or reboot the router. (because the AX23 should in fact automatically reboot at this point)
4) Wait about 3 minutes or so and then check in the web interface of the AX10 whether the AX23 shows up there as an EasyMesh Satellite.
5) In case the procedure was successfull, you can then either leave the Ethernet cable in the AX23's LAN port or plug it back into the AX23's WAN port. (which is likely what most users do)
The "add Satellite" feature of the main router's (AX10) web interface can only add a Satellite by finding it via Wi-Fi first. Therefore, if the router that is to become the Satellite is too far away to be found, then obviously that can't work.
If you want to add the AX23 as a Satellite directly via a wired connection, then you need to use a different method, which is:
1) Either reset the AX23 to factory default settings (for "easi(mesh)ness" you can just press and hold the physical "Reset" button) or switch it to "Satellite Mode" via the web interface. (both ultimately result in the same thing and yes, this also deletes the admin password)
2) Wait 2 to 3 minutes until the AX23 has booted up again, but do not create a new login password on the AX23.
3) Plug the Ethernet cable that comes from the AX10 into one of the LAN ports of the AX23. -> This should initiate the process of adding the AX23 as EasyMesh Satellite. You should notice that the LEDs of the AX23 then behave in a pattern like you usually see when you power up or reboot the router. (because the AX23 should in fact automatically reboot at this point)
4) Wait about 3 minutes or so and then check in the web interface of the AX10 whether the AX23 shows up there as an EasyMesh Satellite.
5) In case the procedure was successfull, you can then either leave the Ethernet cable in the AX23's LAN port or plug it back into the AX23's WAN port. (which is likely what most users do)