Problem powering up 2 NodeMCU´s and 8 * 12vRelays

Samsara_Exit:
I use :

NodeMCU 1.0

Relays (4 channel):

Power step down controller:

5A XL4005 75W

Power supply (12V 3A):

I actually said what parts there. But thanks for this capacitor idea. I will show the wiring bit later.