Popp keypad - use with power supply

I have a Popp with a power supply. In the manual it says that it has to be run with two batteries even with the PSU, which I have found to be bull. The only thing is that with the PSU only Hass shows a battery level at 0. Does anybody else have this running with a PSU?

Also since battery consumption isn’t an issue, I would like to hve it wake up a lot more often. The standard is 604800, I assume that’s ms. Which means ten minutes. So on a reboot of Hass it takes up to ten minutes before this thing actually shows up as anything but “intializing”. But when I try to set the interval to one minute (6000 ms) in node configuration, it doesn’t seem to stick. Does that mean that the interval is fixed in this device, or do I need to do anything else?

I had to press the door bell button to wake it up before I set the wake-up interval! It didn’t get queed for some reason. One problem solved. Partly. Because it doesn’t go from “initialized (cache load)” any faster, I actually have to wake it up by pressing the door bell button to do that