I have wifi bulb (tasmota) installed at the outside of the garage door, one exterior wall and one inside wall between the bulb and router. While the wifi bulb connects to the router most of time, there are a few times that it fell out of the wifi. Even when the bulb is connected, it is very difficult to connect to the tasmota interface.
When I test wifi using my phone at the spot of the bulb, wifi signal are strong. I guess the wifi capability of bulb is too weak? what else I can do?
Try plugging it in somewhere closer to the router and check whether it works correctly there. If so, you will need to add a wifi repeater or access point closer to the garage door.
What version of tasmota is installed ? I remember I had issues with certain builds in the 6.6.0 range (had to install the versions with core 2.3.0 to have stable wifi)
It does work properly. I set it up close to the router and then installed it outside.
I have version 8.1 installed.
OK, 8.1 uses the newer esp core, this is probably not the problem.
Does the light fitting have a metal light reflector that could be blocking the signal?
I didn’t see reflector. There are posts to support the glasses and a cover, could be metal.
The other two wifi bulbs in my front door works perfected fine, which is closer to the router.
When was the house constructed?
What materials are the walls made of?
I was quite surprised how strongly my exterior brick / interior gyprock walls attenuated wifi. Until I had to drag some cables through them and saw that all the exterior walls also have a layer of foil insulation. An excellent Faraday cage for areas without windows.
year 1986, brick and cedar for exterior wall.
Just keep buying access points until you have the coverage you need 