Need help,

I recently purchased a 2 pack Deco X20 unit.

Managed to setup one of the mesh as the main router and the unit work as per advertised.

However, after I performed a firmware upgrade via the deco app, the wifi coverage has gone from best to worse.

I merely standing 9 feet from my main router with clear Line-of-Sight and yet I lost the signal.

I manage to configure the other unit as the main and used it without any issue now.

I have reset the previous router and used it as a mesh and it didn't help.

It keep rejoining my network without needing me to add it up via the deco app, even after I remove it from the network and reset it manually.

I did try using the http uboot method but it prompt with failed message.

I do believe the firmware is somehow causing this issue and wanted to perform another simple troubleshooting before sending it over for warranty claim.

Has been searching on method how to downgrade the firmware but so far couldn't find it, thus really need help if someone can point me to the correct method of downgrading the firmware.