Help with Alexa skill

I need some support today because reading the docs didn’t help me up to now.

Have upgraded from OH 3.4.5 to OH 4.3.8. On OH 3.4.5 various item states have been presented to Alexa “for read only” and worked out perfectly.

Now, on OH 4.3.8, the devices are detected by Alexa but if trying to ask for them i get first a “waiting for openHAB” and then “the server doesn’t react”. The reading is equal to the lower range number defined, e.g. 0 or -5000 for another device. If i change OH settings from “not controllable” ON to OFF, i get a slider in Alexa and can change the values in OH (only the item states but not something at the hardware (e.g. CO2 sensors which are read only). This is strange, but shows that the basic setup between Alexa and OH is working. A normal switch item works out as before on OH 3.4.5.

Are there any known issues with OH 4.3.8 and Alexa?