Navbar Menu links stop working and display 404s

Hi there!

I’ve been having a problem recently, where all of a sudden the links from the navbar (main menu) will stop working and every link in the menu will display a 404, if I go to the shop it will be displayed but there are no products in there. I’ve checked the links from the menu and they all look fine.

When this happens I simply reset the permalinks and the site goes back to normal.
it’s happened a few times in the last 2-3 weeks and I’m worried because it’s like the whole store goes down unexpectedly and been happening very unexpectedly and needs constant attention.

Any help on this would be greatly appreciated.