After upgrading to OH 3.1.0.M3 (running openHABian), some of my item states used in location cards are suddenly listed as undefined, even though the item state updates regularly. This was not an issue coming from OH 3.0.1 stable release.
So, for instance, for an item of mine:
eBusVaillantMQTT_VaillantOutdoorTemperature. As the graph below shows, there are continuous updates for the item.
Regardless, when using the following yaml for the location card, the item is displayed as undefined. The line breaks are set default when saving.
slots: glance: - component: oh-link config: text: "='Outside: ' + items.eBusVaillantMQTT_VaillantOutdoorTemperature.displaySt\ ate" iconF7: thermometer_snowflake iconColor: white color: white style: font-size: 12px