@pappl Update: 

I additionally disabled Smart Connect between 2.4Ghz and 5Ghz Wifi on my Asus Wifi6 AX router and the cams immediately went online and showed up in Apple Home.

Smart Connect switches devices automatically to 5Ghz or 2.4Ghz based on signal strength. So for any reason the Tapo cams announce as 5Ghz capable devices and get assigned to 5Ghz band because the Smart Connect rule is set to prioritize devices with good signal strenght to 5Ghz band.

This seems to be a firmware issue of Tapo cams, isn't it?

There was an update for C220 cameras to fix connectivity issues, hope this will roll out for C225 and C125 too.

  @pappl 

Router: ASUS TUF-AX5400

Update: Today morning the Tapo cams are all offline again, even with Smart Connect disabled.

I don't know what to do else.

  @pappl I have the same issue every day with my FritzBox router. I hope they update the firmware of the Tapo C125 very soon. Otherwise it is not usable. 

  @Markus6789 For the 2,4 and 5 GHz WLAN I have different SSIDs. So the Tapo Cam can only connect to the 2,4 GHz WLAN. Any settings there will not solve the issue, I assume 

I set the router to reject 5Ghz band for all Tapo cams. Still doesn't work.

Camera stays offline when router Wifi goes off and on again.

Problem still persists.

My IP pool is 192.168.50.1 to 192.168.50.255

Firmware Update fixed the problem for C125. Still waiting for an update for C225. It's visible online on Support page, but doesn't show up since weeks in App at firmware update selection. When will this roll out?

edit: still happens on next reboot of router

  @pappl hi, can I ask you hw version and fw version?

I've same problem with 2 c125 with hw version 1.0 and fw version 1.1.12 and the problem persist and they result updated at last version!

Thanks

  @adi_hazard 

Hi, same as yours.

After firmware update the cam didn't go offline after router reboot, but at next reboot it still goes offline.

i set ip adress to fixed 192.168.50.xx but still problem persosts. 😥