We have a similar issue with gallery-app. We open a specific photo from the photos tab and when we return to the tab there is this gap between the header and the photos grid.
On the qml file attached we tried to reproduce the issue. When you click on a number you go to a new page and when you return the grid is not on the same position anymore. It is not the same behavior we have on gallery but maybe it could be related.
We have a similar issue with gallery-app. We open a specific photo from the photos tab and when we return to the tab there is this gap between the header and the photos grid.
On the qml file attached we tried to reproduce the issue. When you click on a number you go to a new page and when you return the grid is not on the same position anymore. It is not the same behavior we have on gallery but maybe it could be related.