I have created a large set (>100) of POIs in My Places on Google Maps. On Android they work reasonably well but on the web version of Google Maps they are often not displayed. I am trying to understand the logic used to decide when they are displayed and what changes I can make to make them more consistently visible.
On the web when I zoom the My Places displayed seems to change at random. Zoomed out most are displayed, zooming in on one it tends to disappear as I get closer, and then reappear when close to the maximum zoom level. When planning a route all My Places vanish except for starred ones.
On Android My Places are visible at all zoom levels and when planning a route, although they cannot be tapped on during route planning but you can at least align the cursor with them.
I am using Chrome, but Firefox seems to have the same problem. How can I make display of My Places more consistent?