importing large KML sets from MapBox Studio

I have some waypoints that I'd like to add to Gaia for my reference. They're in KML files. Some of the KML files are small enough that I can directly import them, and they work fine.

Others are much larger, and I can't directly import them. I've followed the KB artilce about using MapBox Studio here: https://help.gaiagps.com/hc/en-us/articles/115003639948-Import-Maps-and-Data-with-Mapbox-Studio

Over in MapBox, everything goes fine: I can draw my layers and see the points in MapBox. I build a CARTO URL to export the data, and then import that URL using Gaia. 

In Gaia, the new layer appears in my list and I can turn it off and turn it on. But none of the points in my file appear in Gaia. I can't find anything being rendered at all.

The KB article is very old, so maybe something has changed. Is there a new way to do the import? How can I get my larger data sets into Gaia?