I thought it is related to this one: https://github.com/openhab/openhab2-addons/issues/3609
But maybe it is not.
Scenario:
Create a channel for a thing, let’s say a number (like in my example before):
Type number : ventilationMode "Mode" [ ga="9/5/3+9/6/3" ]
Create a related item and put it on a sitemap for testing. Save all your files so the changes are applied by OpenHAB. This will work. The next step is the one that is broken.
Change the configuration of the GA. E.g. you realize that the default for numbers is 9.001 (2 Byte) but you need 6.010 (1 Byte counter) for it. You change the configuration to:
Type number : ventilationMode "Mode" [ ga="6.010:9/5/3+9/6/3" ]
and save the file. OpenHAB will tell you that it refreshed the information. But actually it didn’t apply the change of the DPT. If you enable tracing you will see that OpenHAB still handles the channel as DPT 9.001.
There is another thread mentioning that they experienced that issue as well:
If you think that it is not related to the issue on github that I mentioned before, I am happy to file an issue.