Can't get EL4001 to work - all other devices work

Hello,

I added an EL4001 analog output terminal to a system with a few other Beckhoff terminals, which is otherwise fully working.
Like the other terminals, the EL4001 shows up with "ethercat slaves" and this as well as its status LED shows it's in the OP state.
I added it to the ethercat-config.xml like the other nodes:<slave idx="4" type="EL4001" name="spindleSpeed"/>
I also tried setting it up manually like here .

Unfortunately, I can't get any output voltage out of it (other than zero) using the pins as documented  (I set the pins using halcmd and verified with Halscope). As mentioned, all other Ethercat devices (mostly Beckhoff) work without issues. I also tried changing the order of the Beckhoff terminals, but that didn't help (as expected).

Does anyone have any idea what could be the issue here, or what I can do to further debug this?

Verify that the slave has the entered PDOs with "ethercat -p 2 pdos"
Check syslog for any messages, last lines of "sudo dmesg"
If that doesn't give anything, add debug messages "ethercat debug 1"
 restart ethercat master, start linuxcnc and check syslog again for any helpful output.