@SteveQuinn: I'm sorry to hear that you're experiencing this issue. Although I understand that you have checked Settings > Advanced Features > Continue Apps On Other Devices, and it is enabled on both devices, please can you also check the following.
1. Both devices must be signed in to the same Samsung account
2. Both devices must be connected to the same Wi-Fi network
3. Both devices must have Bluetooth enabled
If you have checked the above, and everything is set up correctly, then please can you confirm if you're still able to copy and paste content as standard on each device?