Strange WARNING in the log

I found this WARNING in my HA log but I don’t understand which is the cause of it.

2024-01-17 17:40:48.610 WARNING (MainThread) [homeassistant.components.mqtt.mixins] Entity category `config` is invalid for sensors, ignoring. This stops working from HA Core 2024.2.0

Does anybody know how to trace and find the problem?

I have HA Core 2024.1.3

Thanks Marco