OnOff SHIM - Pi is still auto-powering on with plug

I got a couple of OnOff SHIMs for a project I’m working on on where I want to be able to have a nice little set-and-forget gaming box. I am powering a Pi zero using the SHIM’s microUSB port.

My SHIM works fine for powering off the pi and turning it back on if it was shut down, but for some reason the Pi still automatically turns on whenever I plug the SHIM into power rather than waiting until the button is pressed.

Is this normal behavior? Or does this mean one of the pins on the SHIM wasn’t soldered correctly?
I want a device that doesn’t turn on unless I hit the switch first.

mine works same way ,so i think it normal

The official description for it says:

Just plug your micro-USB power supply into the micro-B connector on OnOff SHIM, and then press the button once to switch on power and boot up your Pi.

This suggests that the OnOff SHIM is normally supposed to be off when you plug in power?

just checked mine, and I made an error in my post above ,just checked mine and do remain off until i push the shim button to turn it on.