I'm trying to cascade multiple 74HC595 shift registers to expand the number of digital outputs in my project. While one shift register works perfectly on its own, as soon as I add the second (and especially the third), I start getting strange or inconsistent output—some LEDs don’t light up correctly, or they shift out of Order. Is there a timing issue I might be overlooking? Do I need to delay between latching and shifting? Could signal integrity or voltage drop be the issue when chaining several ICs?