Light is found by the TAPO app but fails to pair with solution - old version of Android on the phone
I recently bought four P100 switches and one L510B(EU) lamp. I set up three of the switches with no problem at all using a Sony Android phone but when I went through the same setup for the lamp, it shows the correct list of SSID but then fails with the message "failed to pair device".
On my phone, it is left connected to the bulb access point "Tapo_Bulb_5B51". The properties of that connection are:
IP address (allocated to the phone): 192.168.68.100
Gateway: 192.168.68.1
Subnet mask: 255.255.255.0
DNS Gateway: 192.168.68.1
Trying to open a web page to the gateway returns only the message: {"error code":-1009}
In case I had reached some limit on the router, I then set up the fourth P100 switch and that went through with no problem.
I tried this several times, did soft resets at least six times and a hard reset to factory defaults twice with no luck.
Having found a similar thread on this forum, after typing most of this post, I decided to try a different phone. Using a Motorola G50, the setup worked perfectly first time. This phone is running Android version 12 whereas the older Sony Xperia was running Android version 9.
On setting up, the bulb immediately upgraded its firmware from V1.0 as shown on the packaging label so this problem may only be relevant for V1.0.
I have posted this as it may help others with a similar problem.