Network Packets Filtering ( I really dont know )

[sexyman]

Hello, Usually I don't post here until I face a wall 
I recently moved to Germany and installed internet connection with Vodaphone 
The package I picked gives modem for free or I can upgrade and pay 3 euros more to get a "wireless one".
I simply chose the free modem 
after the modem arrived, I started configuration and I noticed that this router is normal (wireless) router but the wireless feature is not booked, I checked on Vodaphone forums and saw that you have to pay to get this feature. I don't like how companies use such ways to earn money.
That's why I bought a TP-Link router and connect it to the Cgb Vodaphone router and it worked fine.

 

Until I started noticing connectivity problems like


 

•  Multiple Iphones connecting normally like 5mins and then apps like WhatsApp fails to connect, some apps like eBay loads the ads but not their photos, in all this, apps like youtube or chrome works fine 

to restore WhatsApp connection I have to disable wifi and reconnect on Iphone like 2 times and it will work again fine
 

•  My TV which is connected to the Cgb router via ethernet, sometimes it takes the tplink network ip which leads to issues like Youtube is working fine, but all other apps on tv fail to connect to the internet

anyone who knows how to block tv from entering the tplink network please answer 
(tplink TL-WR841N) , I guess wireless mac filtering won't make the result since its (wireless and we're talking ethernet)

noting that connectivity with the laptop is going great so far

anyone with same experience, knowledge or any key to help i would really like to solve the problem 
without paying more to the company for nothing

[sexyman]

Solved , I disabled the DHCP from tplink router