When i redeploy my SharePonit spfx extension, the new site column name never refresh. I tried to delete the app and redeploy the app. Or even change the version number in package-solution.json. It is no hope. The steps i pack the sppkg file are:

gulp cleane
gulp bundle --ship
gulp package-solution --ship

This issue is reported to github https://github.com/SharePoint/sp-dev-fx-webparts/issues/472