While browser cacheing is a good thing especially on mobile devices because it minimises the amount of bandwidth needed to display your maps, it can cause some headaches when you are trying to edit an existing map border or block json file. Sometimes no matter how many times you try to refresh your browser, the app still displays the old version.
The solution is to rename your files with each edit. For example if you are trying to edit the border on map-10.json then you would rename the edited file map-10a.json. This will mean that you would also need to rename any of the other two files as well so map-10-blocks.json would become map-10a-blocks.json and map-10-labels.json would become map-10a-labels.json respectively, even if these were not changed.
The final step is to go to your manage maps app and change the name of the "Json File Name" to map-10a by going to "Maps" and editing map 10.
This will force the new file to served when you go to map 10 in your CongMaps app.
With each edit simply increment the file name i.e the next edit would be map-10b.json