Hello @ALE1965
Through your own troubleshooting via trying the SIM card in another phone and it works as it should this points to the phone at issue.
If a soft reboot or as a last resort a Back-Up and Factory Reset do not resolve the issue then I would suggest first contacting the Manufacturer for support initially and if then required visit a Vodafone Uk Highstreet Store where they can look it over and if necessary send it off to their repair centre.
Take time and date stamped pictures of the phone with one of it turned On and if possible one of any visible water sensor.
I’m assuming their are no visible marks on it from an accidental drop or it’s not been in water.
On eligible contracts the Vodafone shop can offer a courtesy phone if they have one available.
Current Phone >
Samsung Galaxy s²⁴ Ultra 512gb.
