No 4G and wifi

I have no internet connection on my iphone xs whatsoever :(. Wifi works everywhere in the house, and my phone carrier already sent me a new sim card with no results. Because of this reason i cannot turn off "find my iphone" to reset my phone to factory settings. (I already rebooted my phone 10x, multiple "hard resets" but nothing works). I even deleted my phone "from find my iphone" through iCloud.

The weird thing is, i can call and receive calls, and messages as well.

Please help me out!

(and sorry if i've made any mistakes, English is not my first language)