Does the obscuration bounding box cross out of the location filters for the project? It looks like it is close to a coastline. If any area of the obscuration box is outside the locations included in the project filters, the observation won’t be included in the project.
That particular observation shows the smallest encompassing places as either Hong Kong (Country) or Islands, HK (District), but I find neither of those in the places list for the project. Maybe adding Hong Kong to the project will fix it?
It seems like the system is working as intended to me, based on what @twainwright wrote - obscured observations from small locations will not appear in collection projects for those locations. You can also make a traditional project to collect obscured observations.
I’m changing this to the General category since there doesn’t seem to be a bug.
The project is a collection project, and the borders do look to be the issue as described above. There’s no way around this with obscured observations and small locations in a collection project (see linked post above or read others on the forum for explanations). If you want to gather obscured observations for a project, you’d need to use a traditional project which allows for manually adding observations.