Node-red blocks Python script

[Ilovemyhous]

Hello!

We use a Raspberry Pi (3B), a P1 cable, and a python script from this repo.
The script works fine, and outputs the data as, what looks like, JSON form.

The problem is, when setting up the smartmeter node, choosing the protocol, transport etc., it crashes, apparently the serial port, since the python (decrypt) script sends the following error ERROR, expected 0x82 separator byte not found, dropping frame.

Our first guess was maybe some serial issues, but we tried different settings in the node, without much success.