I fil up the tank last night and noticed that the total mileage left had not changed will it correct its self over time

How far have you driven between filling up and and now ? Jules

Range on mine updated as I drove out of the filling station. Best ever was over 600 miles after a nice economical run down the coast of Loch Fyne.

Probably only 8 miles, it usually updates after filling the tank will give it time

Did the fuel gauge register that you’d put in fuel?

Yes the white bar went upto 100%

Try resetting the trip A and B. See if that works? 2013 FL2 XS.
Defender 90 300 TDi.
Defender 90 300 TDi CSW.
1964 MGB Roadster.
1944 Willys MB "Jeep" with bullet holes. (gone)
17 hand Irish Drought Thoroughbred (mostly lame)
Nagging Old Boiler.

Mahatma Gandhi said if there is an Idiot in power those who elected him are well represented. The Enemy is our own corrupt Government.

I've actually had this b4 when I was on holiday down south I just ignored it and it corrected its self next time I topped up I usually go by the 1/4 tank indication on the fuel gauge to top up

That does seem a bit strange- mine updates pretty much instantly based on the current mpg .

I suspect you have a dodgy fuel gauge sender/connection. But I'm unsure how to test for that.
The vertical bar graph fuel level display is obviously an electronic thingy and very different to the old fashioned "Smiths" gauges that I'm more familiar with. Jules