Whisper stops working with error: __main__.py: error: argument --beam-size: invalid int value: 'null'

Hello. I just set up Whisper from the add on store today. At first I tought it was working correctly, but then it stopped working and the addon log is the following:

[17:50:26] WARNING: Your CPU does not support Advanced Vector Extensions (AVX). Whisper will run slower than normal.
usage: __main__.py [-h] --model MODEL --uri URI --data-dir DATA_DIR
                   [--download-dir DOWNLOAD_DIR] [--device DEVICE]
                   [--language LANGUAGE] [--compute-type COMPUTE_TYPE]
                   [--beam-size BEAM_SIZE] [--initial-prompt INITIAL_PROMPT]
                   [--debug] [--log-format LOG_FORMAT] [--version]
__main__.py: error: argument --beam-size: invalid int value: 'null'
[17:50:27] INFO: Service exited with code 2 (by signal 0)

Keeps saying this again and again. Changing model and/or beam size does not help. Uninstalling and reinstalling the addon make it work for a while, but then it stops again.
Am I doing something wrong?
If it helps, in the config I set “language” to “it” (italian). HA runs on a mini pc with a celeron J4125.