Installed the latest software via the experimental HA addon (which supports --lang) and configured to use Hungarian language.
My HA display language is English.
Getting similar entries in the log:

Jan 28 21:45:24 homeassistant homeassistant[631]: 2025-01-28 22:45:24.436 INFO (MainThread) [homeassistant.components.mqtt.binary_sensor] No matching payload found for entity: binary_sensor.wolf_fgb_0x3_250019_zuendung with state topic: Wolf/192.168.20.10/FGB_0x8/Zuendung/text. Payload: 'Ki'
Jan 28 21:45:24 homeassistant homeassistant[631]: 2025-01-28 22:45:24.437 INFO (MainThread) [homeassistant.components.mqtt.binary_sensor] No matching payload found for entity: binary_sensor.wolf_fgb_0x3_250020_brenner with state topic: Wolf/192.168.20.10/FGB_0x8/Brenner/text. Payload: 'Be'

Ki and Be correspond to off and on but I think the entity values should not be localized.
Turning switch entities on or off is also not possible and all switches come up in a weird way.
I think it should be related to entity default states, but I think it is on/off and not localized even if the HA display language is different from English.

It seems to me that the HA discovery logic should not do this: https://github.com/zivillian/ism7mqtt/pull/155/files#diff-dfd5ab0b3144df7715a9a458831683a18839a6c43de1277b377ee558572a5e2dL269

For entities that have only on/off state and not a string state. Unfortunately I can only read in this programming language but hope it can be fixed.