IPhone 8+ doesn't receive calls right away and problems with connecting to internet?

I have an iPhone 8+ and I've always had problems with sometimes not receiving calls for 1-2 days after someone called me. That's not often but it's happened, and texts sometimes don't appear for a couple hours after they were sent to me.

Also been having a problem the past 2 or 3 weeks with slow internet connection, or none at all. My data sometimes doesn't even work. But everybody else in my house has no problems.

What could be the deal? I've restarted the router, my phone, and no change.

Your 8+ is still under warranty. Call apple

  • Why doesn't my right headphone doesn't make sound? I have the iPhone 7 EarPods (not the Bluetooth ones ) They were working just fine until one day I realized that there was no sound coming out of the right side. I already cleaned it but doesn't work. How do I fix this?
  • Why doesn't my iPhone send or receive calls or texts? I purchased an iPhone second hand on t-mobile, 3G works fine but can't receive any calls or texts or send them. Thought the IMEI might have been blocked. Any ideas?
  • My iphone 5c doesn't receive misses calls or voicemails when off? When my phone dies and then I turn it on I only get text messages but it never shows I got any missed calls or voicemails when I know people have called? I'm waiting for a important call is there anyway to receive my missed calls and voicemails? Its kind of a big deal and I lost my charger so its been dead until now and I want to retrieve my calls. I don't have it on do not disturb or any of that.
  • My iphone 4s was stolen and I replaced it right away with my old sprint phone? But now everyone who is txting me on an iphone it goes to the old iphone and the man who stole it is responding. I never signed up for ICloud or anything. How can I turn off imesaage on my old Iphone 4s, if I don't have it. Or how could I completely turn off that phone. We already called sprint, they had no idea what to do.