HI @vampire27 Welcome to the Samsung community 
Is the issue with your Data or wifi Connection, have you tried much Troubleshooting.
If this is issue with cellular conection try the following:
Run the Diagnostics check to see if any issue is detected- Samsung Members-Support-Phone Diagnosics.
Check that mobile Data is enabled and that you have the latest updates. Try a soft Reset of your Device which can sometimes sort issues,press and hold the power and Volume Buttons simultaneously for around 7-10 seconds until it Reboots. You could also try toggling Airplane ode on and off, needs to disabled for Mobile Data. you may though need to Reset your Network Settings. go to General Management-Reset-Reset Mobile Network Settings or you could try Reset All Settings.
if not solved you mat need to reinsert the sim card to see if that makes a difference and cherck if any issues with your Network. other ideas are to try in Safe Mode where 3rd party apps are disabled, if ok here would pinpoint recent third party apps which have been installed. https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/
other Troubleshooting is to clear the cache partition, temporary cache files are deleted but Data is intact. sometimes tnhese temporary files can be outmoded or even corrupt.
Follow these steps:
1. Turn off the device.
2. Connect To Computer , other Device or TV USB, Press and hold the Volume Up key and then press and hold the Power key
3. When the Android logo displays, release both keys.
4. Wait until the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.
