Anyone know a step by step process to fix this please ?
A good old restart is usually the silver bullet here, which can be found under the settings dashboard.
However if you are comfortable with command line you can also use this script instead of a complete restart:
- SSH into your Umbrel instance
- Run the following command
sudo ~/umbrel/scripts/stop && sudo ~/umbrel/scripts/start
Thanks, it says : Umbrel must be stopped as root
Please re-run this script as
sudo ./scripts/stop
I ran : sudo ~/umbrel/scripts/debug and got 
==== Result ====
================
The debug script did not automatically detect any issues with your Umbrel.