why accordion moves (down to up) from when loading the page to after loading page? (see screenshoots)
Welcome to our forum.
This is happening because of loading icon at top visible when page loading and hide when page load completed and then it is hidden and accordion is visible when loading icon hides it creates empty space at top and accordion jump to fill that gap. Please see the screenshot what happening here
Not sure which version you are working, i will try to fix the issue.