PNG "Transparent Background" greyed out in ArcGIS Pro 3.3.0

[KShill]

I just updated to ArcGIS Pro 3.3.0 and suddenly my Export layout to PNG is missing the "Transparent Background" feature. The checkbox is still there but it's greyed out. Just before the update, I was happily exporting transparent backgrounds from the same project all day. What gives?

[DanPatterson · Accepted solution]

Export to PNG—ArcGIS Pro | Documentation

check your color depth according to the help topic