Various Apple Watch issues - not syncing activities to iPhone; won't unlock Mac; no GPS of activities

Hi

My Apple Watch 4 has just recently encountered a few issues all at once. My activities no longer show my route (e..g when I was running). Just shows where I started. Activities have stopped syncing to iPhone (XS). I can see the activity in my watch, and iPhone has go the same exercise minutes/calories burned etc - but doesn't show that I have completed an activity. This has been all activities for the last few days. Also, my watch has stopped unlocking my Mac? I have gone through all the checks to ensure they are synced etc. Airplane mode isn't on. Bluetooth and Wifi all in order. Tried unpairing and re-pairing my watch. Hasn't helped. Has anyone got other suggestions - or is this a wider software issue?