@Solla-topee 

I am experiencing the same issues as described several times in other posts.

I have a C410 camera which worked fine until about 1-2 months ago when it simply started going offline and doesn't record anything.
I used to have the camera outside connected to the solar panel and initially I thought it was a battery issue (not charging enough due to lack of sunlight - winter), but I also tried connecting it directly to a power source and the issue remains. 
I did no changes to my network, I have a Deco mesh system in place and several other Tapo Camaras (3*C210, C520, etc) connected to the same system and they work fine.
I've tried putting the camara directly next to the Wi-Fi, with no changes.
The only time when the camera is able to detect any movement is if I'm accessing the camera directly and am viewing it live.

I've turned on the diagnosis, but when checking the log, it doesn't really seem to help.

What else can I do?