It’s horrible and been like that since they released this feature. Don’t do background but do foreground and it should work. Otherwise I usually have luck just making a workflow action and picking the “download as a csv file” action and doing it that way as that seems to work well also. Getting data in and out of Bubble is my #1 complaint with it, as even when csv export does work it’s so basic in that it doesn’t even let you add columns from related data types to it.
Sounds like something might be off here. Would you mind filing a bug report please so we can look into your specific app and the view you’re trying to export?