[Bug] about visualChannels.sizeField

**I use python to create a html. and I set sizeField successed. When I open the web page, **I check Height Based on**, it is OK,but the map display content is wrong. The content is same as default(based on count of points). Then, I click coin 'X' on the right, and choose the column I want to see in the map, the display content is right. **

`
"visualChannels": {
"colorField": {
"name": "num",
"type": "integer"
},
"sizeField": {
"name": "num",
"type": "integer"
},
"colorScale": "quantile",
"sizeScale": "linear"
}
`

Reproduce the map with the provided visualChannels.sizeField configuration, then trace how the initial map applies sizeField versus the default point count. Compare that behavior with selecting the column through the map UI; done when the configured size field is used on initial load and matches the interactive selection.

Written by the indexing model from the issue text.