We got a quick response from Garmin. Its actually a bug in the underlying approach data, but that apparently ongoing bug is now handled by the navigators operating software. The reported issue doesnt have anything to do with database capacity. The issue began when some IAPs with LP lines of minima were coded with a Vertical Descent Angle (VDA) of 0 degrees. Software did not expect this as the IAPs are not supposed to be coded with VDA=0. If the IAP has no VDA (noted as Decent Angle NA on the chart), then the navigator can fly the approach as an LNAV-only without vertical guidance. If the IAP is coded with a VDA of zero, Garmin makes the approach unavailable from the database. Later software corrects this anomaly and restores the IAPs with VDA=0. Note that there was a Service Advisory Garmin sent out in 2013 when the issue was identified and they started to filter the affected IAPs from the Navigation database.