@Mike801 on a Smart Remote you should be able to use the Colour coded Button(Red,Green,Yellow,Blue).press this button and select, there should be option for previous channel. others ones are the likes of record and Cable Box You may also be able to bring previous channel up by pressing the return Button for at least one second. on a standard Remote there may be a dedicated button.
Some information here https://droidrant.com/what-do-the-buttons-on-a-samsung-remote-do/
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.1,Android 13 .
