Oh come on, whatever do you mean by that?
What does this have to do with a 12 V power supply?
Something that was missing from the previous discussion.
You can only use the “barrel jack” on a UNO or the “Vin” pin to supply 12 V (and no more) if you are not proposing to power anything of significance (which is to say, requiring more than 50 mA in total) from the output pins plus the “5V” pin.
You appear to be connecting relay modules to the 5 V pin. They require power as well as whatever other modules you have there; you need a proper 5 V regulator to power them, generally a 5 V switchmode “buck” regulator is what you need.