Hi Stefan,
what i see in your widget is that you have placed all content with “absolute” positioning, everything what goes in expanded is nicely in rows and colums. i believe this is the root cause. This does not explain why the position absolute is disapearing, but as a test if you just remove the absolute element from the gras, it obviously will be re-positioned like everything else ( as absolute is related to each other ), but if you do the test then with expanding and colapsing, the gras is still there where it was. I believe to sort the problem, you need to work in rows and colums to properly position the elements within the card-content part of the widget unless someone has another solution.
There is a nice discussion in another post around this topic of placement, this might eventually help: