Camera flash not working properly

I have an iphone 11 Pro max.

On Saturday evening when tried to I turn on Flash and pressed the Flashicon in the top left, whilst on photo mode, it lost the cross through it and remained white and the flash did not flash, When I expanded the menu and used the Flash option which appears at the bottom of the screen, it did work.

Sunday evening, I tried again and the top left flash icon went yellow and the flash worked.

This morning, it is back to functioning as it did Saturday, ie the cross through the flash disappears, it remains white and the flash does not function, Has anyone else had this occur,

I am sure it is a bug and will be resolved in due course of time.

[Re-Titled by Moderator]