@Zagreb 

Hi, can I have some pictures of your IPTV setting on the Deco?

Have you seen this FAQ before:

https://www.tp-link.com/support/faq/2421/

And when you mentioned that ‘after the IPTV configuration, Deco would crash down’, would all the Deco turn red as well?

Thank you.

@Zagreb 

Hi, I noticed that except for the Deco, you have another NAT router-- Speedport plus, so may I know before using the Deco, did STP work with Speedport plus directly without any additional setting or still IPTV/VLAN ID required?

Can I have some pictures of the IPTV configuration?

By the way, when all Deco turned red, was the IPV4 internet IP address still here on the Deco APP?

Thank you.

@Zagreb 

Hi, if the STP worked with speedport plus directly without any additional setting, maybe we did not need IPTV/VLAN ID;

How about choosing the IPTV mode to Bridge?

Thank you.

@Zagreb 

Hi,

Have you checked with the Croatia Telecom before that the STB needs to connect a specific port on the Speedport plus router, or whether they allowed adding another router to bridge the  IPTV connection?

Or would it be suitable to replace the Speedport router with Deco and set up the IPTV VLAN directly on the Deco?

Thank you.