Since my post, I have sent the watch back to Samsung so they can try and diagnose the issue. They cannot find anything wrong with the watch and have sent it back, stating that it may be down to third party apps, network conditions or how the device was being used.
They recommend testing my phone, which is a Galaxy 21 Ultra. There's nothing wrong with the phone and it's just received the upgraded operating system 7.
In summary, it's still not working!