74HC125 Buffer not works with Shift Register 74HC595

I attach a circuit where I plan a raceboard to show time with 6 diggits und for place 1-3 and actual time.
I plan a daisy-chain of 24 shift register where 4x6 digit to show these 4 times.

In my first step i have a daisy-chain with 24x 74HC595. From uno ich go with SPI trough the register.
Here is a video where you can see my first step.

with 12 of them all was ok. But after that I have the problem that I get errors.
You can see see this in the video.

So the plan was a buffer between the uno and the rigister.

Here ist my circuit with a buffer in the attachment
Today I test it but nothing is going on.
I put the ss-bus from uno in the input of the buffer. From Output I go two the first register.
But nothing is going on. The clock I set down.
Hope anybody can help me.

You are really head-banging!

You need three MAX7219 chips. Drives 24 seven-segment displays, good brightness, easy to program. Three resistors and half a dozen capacitors.

Even if they are expensive to buy in DL, the improvement in the design will be worth it.

it is right. I have tested with one max7219. I have buyed more so I can test it. In my first test I saw that I need not so much cable und wirring with a max :-) For my current project it is better when I do this with max.

For my learning I hope for more information about buffers. I read the last day and saw that I have planing and connection errors in the buffer. The ports that are not connectet need a connection to low or high or?

Open gates not work. The signals from uno are high so I must set the pin unjused pins to low. Is that right?

Interfacing LED displays with the MAX7219 driver

I have done this yesterday with tree of max7219. this works perfect and is easy to wire. not so much cable. But for my learning I will do the same with shift register and with a buffer. now I wait for 100n to do the next steps with the buffer.