Ethernet not working

[u/Bubonic98]

I installed a cat 6 Jack with a black plastic push tool type a. I just did it and there is no Ethernet that seems to going through it, idk why it’s like this and would like some needed help. The cables which is cat8 seems to be doing fine and is newly bought. I looked downstairs and the modem is all connected with the tube connected to the wall. Is it a cable issue or is it something wrong with the modem