Update: Today my cameras received the update to 1.3.11 through the automatic update which seems to fix this issue for me.

  @BjoernD how did you get that update?

My camera stopped working with ispy after 1.3.9 firmware update 

@Solla-topee 
@BjoernD wrote in Firmware 1.3.11 that his camera received a new firmware (1.3.11) and its working fine again.

How do i get the new working firmware???
n my Tapo App there is no notice for a new firmware. My C200 is still on v1.3.9 !

  @Solla-topee 

1. The model number, hardware version, and firmware version of the camera.
Model: C200

Hardware version: 2.0

Firmaware: 1.3.9

2. Please describe your network diagram, such as the internet cable--wireless router)))(((Tapo camera, phones, ONVIF devices, etc.
Tapo Camera connected directly to Wifi router, provided by Vodafone. No restrictions on internal ports, such as 554.

3. What app/program(such as VLC, iSpy, etc.) do you use to stream the camera via ONVIF protocol? Please check if you can stream the camera via RTSP protocol.

I'm using VLC, in a computer connected in the same network (same router), trying to open a network stream, with rtsp://user:pass@192.168.1.xxx:554/stream1

  @Nic77 

The firmware has been available in my app. Not sure, if it has been released in advance for a limited group of users.

Hi @Solla-topee ,

in the meanwhile i got firmware 1.3.11 Build 231225 Rel. 53270n(4555).
But the access via ONVIF is still not working correctly:
The stream comes with 1 fps! and the connection interrupts randomly after a few minutes.

For testing purposes i've installed the C200 next to the router (FritzBox 7590, 2.4 WLAN, distance: 1 meter)!

It's getting annoying: i bought a C200, all is working fine, you recommend to upgrade to the newest firmware, but therewith the device is getting unusable!

So: please tell me how to downgrad to the old working firmare 1.3.6!

Kind regards,
Nic
 

Same issue here - I had C200's first gen working fine with ONVIF via Scrypted. I bought some new C200's and they were Gen 3, didn't work at all, whilst Gen 1's did. 

Then after the firmware rolled out on the Gen1's, they stopped working. I know have FIVE C200's and NONE of them work via ONVIF anymore - and NOTHING HAS CHANGED with wifi setup / configuration / passwords etc.

ALL CAMERAS STILL WORK WITHIN TAPO APP.

We need an answer TP-Link!!! This is clearly an issue, we are all saying the same thing. Are you listening?