The issue could be with your local and surrounding Vodafone masts.
Weather conditions, trees, buildings, population growth and mast congestion can affect your user experience.
Take a look at your Vodafone status-checker.
So may I ask does this happen everywhere you go or in a particular area ?
Your phone has a built-in diagnostic tool via your Samsung Members App under the GetHelp Section.
In your phone's Settings, Connections, Mobile Network's, Network Mode choose 4G, 3G,2G Auto Connect to see if this helps.
A Samsung Experience Store or Samsung Service Centre can take a look at your phone too.
I wish you all the best with this.
Current Phone > Samsung Z Fold³ 5G.