Remote receiver not working as expected on the CBU (BK7231N)

[spupetic]

I have installed ESPHome on a CBU based 433 MHz wireless doorbell. It has a doorbell chime chip (that works well via the remote_transmitter component) and a CMT2217B OOK RF receiver, which does not work somewhy. I can confirm that the RF receiver itself works with ESPHome on an ESP32.

Here is the code for the protocol decoder:

https://github.com/pauln/esphome-linp-doorbell-g04/tree/main/components/linptech_g6l

I don't get any errors or warnings, except that the PIN should be inverted, but when I invert it, that doesn't change anything. By setting the log level to very verbose, nothing useful comes up, it seems like the protocol decoder never sends log messages.

My settings for the remote_receiver:

remote_receiver:
  pin: 
    number: P8
  dump: linptech_g6l
  filter: 20us
  idle: 900us