I have reinstalled my Raspi with OH 4.0. With the version I now see a change when I add equipment to the model. Some equipment is not displayed.
Procedure:
create equipment from thing ( on a location)
choose it and mark the channels
add to model
After this the Equipment is not on the model. I can see it under the items, equipment and channels. All there and working.
See screenshots for a example.
If you are using Firefox this is a known problem without a solution. Firefox caching works differently from Chromium based browsers and doesn’t refresh correctly. A force refresh will show the newly created equipment in the model and Items.