Hello  @SirRicky 

For ' my ios and andriod device cant have stable connection with my tapo.' do you mean the camera become offline in the APP, or you just can not watch live view, or app crash can you share a photo of error message or a video of it? What is the model and OS your IOS and Andriod phone? Thanks. 

You could connect mobile device directly to the Home Wifi network and see if you have use the app stably under local home wifi network?

Turn off VPN service on the mobile device. 

Confirm the APP and device firmware are both up to date.