5V power supplies RPI4

[mgrouch]

I am trying to stabilize my power for a RPI4 OP2 build.
I was using a LM2596  buck converter 3 amps max but I was getting the the low power warning.
I had to up the voltage to about 5.35 volts then no warnings?
I switched to a XL4015 rated for 5 amps max but I have the same issue. This has to be hard on the voltage regulator on the RPI?
Or is my meter bad?
 I am only drawing .54 amps @12 volts and that includes my USB Hub that has its own power. The Pi is drawing less then 1 amp @5 volts this is well within the range of both Buck converters.

Only the powered hub is plugged into the USB and i have the IMU and BME so power draw is at a minimum.
The connection to my 5v pin is though a pi52.com proto-hat the wire is 20 gage and about 2" long round trip.

Any Ideas?

what is vl805 firmware version?

sudo vl805 

Should output it. 

.54 at 12v is a bit high. 
I have very much same set up
and for me it’s
.45 at 12v

I have issues with self powered hub. 
(Unrelated) rp4 reboot doesn’t happen. 
It just shuts down. 

I would use couple Geekworm X828 SATA board (made by SupTronics Technologies) with their X710 power board. With those I wouldn’t need internal USB hub and 12vDC to 5vDC internal step down converter and save on cabling. 

Currently I use TOBSUN EA50-5V DC 12V 24V to DC 5V 10A 50W Converter Regulator 5V 50W Power Supply Step Down Module Transformer