Questions about 2/5 and 4/5 of the tutorial video "Data"

I am always happy to help.
The tutorial videos have always helped me.
I would like to ask for a solution to a problem that I stumbled upon while watching 2/5 and 4/5 of the tutorial video “Data”.
I tried following the tutorial videos, but when I made additions and changes to the listings, I could not get them to take effect immediately.
I had to exit and enter the screen to get the additions and changes to take effect.
Therefore, I would like to know how to make it so that the changes are reflected as soon as I type them in and press the button.
I had a similar question before and was told to uninstall the app on my phone and reinstall it, which I tried but was unable to solve the problem.
Thank you in advance for your help.