My Lebara SIM card on my phone has slow connection

[KitKat Gaming2008]

Hi! I have a Lebara French SIM card on my phone. My mom registered me on Lebara to have Internet on SIM card. After registered successfully, i got an SMS saying me the entered code is not valid and i need to visit the link po.st/Frfr (see image #1). The link didn't work (see image #2). Testing Internet Mobile Data in my Lebara SIM card give a slow Internet Connection. Testing my Mobile Data Connection by visitng google.com resulted in DNS_PROBE_STARTED (see image #3) then DNS_PROBE_FINISHED_NO_INTERNET (see image #4). I have 4 images where i encounter problems with my SIM card:

 

[B. Diddy]

Are you sure you registered successfully? The message you received that the code wasn't valid makes it sound like it wasn't successful. Have you contacted Lebara customer support about this yet?

What's the exact model number of your S6? There are several variants intended for different regions of the world, so it's possible your variant doesn't support Lebara's network bands.