The DCI is added to a node (in this case by a template but can also be manually added) and its working perfectly fine. Yet when I try and select it from a list i.e. making a network map/graph/dashboard/anything where I can choose a DCI, an entry sometimes just will not show up at all. Only way I found to fix it was to remove the DCI and re-add it again. But this causes me to lose all existing polled data
And even then sometimes it doesn't work and I have to actually duplicate a DCI, the duplicate will show up but not the original

I've had this issue periodically for years, and when it happens its frustrating as I need that data, sometimes its data thats been silently collecting for months and then I need to put it into a dashboard but am unable to
If I manually go to the node and then last values tab, right click and choose 'graph' the data is shown just fine. And if I right click on that graph and choose properties->data sources I can see its in there. But if I choose 'add' and browse to the node, that DCI still does not show up

Is this a known issue?
I propose a short-term workaround if it can't easily be fixed: Allow manually typing in the object number of a DCI instead of having to browse to the node and choose it. Maybe then it'll pick it up and at least allow me to add the data source, even if I have to go and look it up manually