Thanks for your presentation https://arduino.stackexchange.com/tags/max7219/info. You say that multiple MAX7219 8x8 blocs can easily be daisy-chained and you show an example of at least 12 blocs displaying "Testing12345". Trying several programs I found for Arduino, I never succeeded to chain more than 8 blocs with 8x8 matrix (either 8 individual blocs or 2 groups of 4 as on your image). So I'ld be very happy if you send me examples of programs managing more than 8 blocs for fixed or scrolling displays. Many thanks in advance.
Try using @Majenko 's MAX libary https://github.com/MajicDesigns/MD_MAX72XX . It allows you to specify how many modules are to be addressed.