My iPhone SE will not pair to my iPhone se

iPhone SE unable to fully pair to Apple Watch Series 3/Watch won't update

As the title says, I'm having trouble getting the pairing/update process to work for the Apple Watch Series 3 (and iPhone Se). Upon pairing my iPhone SE to the Series 3 Apple Watch (via "Start Pairing" and either typing the 6 digit code or using the camera to find the watch), I'm greeted with the message of having to Update my watch to 5.3.7 if I want to be able to pair my Watch to the phone, where the other option is to Exit Setup and Start Over. So, I tap "Update Now" which leads to it saying that it's checking for updates, before it ultimately gives the message "Unable to Check for Update - Checking for a software update failed because you are not connected to the Internet." I am absolutely connected to the Internet. The options are to Start Over or Try Again. Try Again obviously doesn't do anything, and Start Over simply unpairs the two devices and I'm back to square one.

Things I have tried/things that I am making sure to do:

• "Start Over" option, at least 5 times over
• Resetting both devices at least 5 times over, as well as one or the other multiple times
• Turning off and on Airplane mode
• Resetting the Internet connection
• Turning off cellular data
• Connecting to a different Internet connection
• Disconnecting from internet connection (ie using cellular data only)
• The Apple Watch IS connected to the charger
• The iPhone IS connected to the charger
• The Apple Watch shows up in Bluetooth on the new iPhone, and does not on the old one