Desktop layout drop down dont when starting in tablet width

When I start my page which is using this theme in a browser window which is smaller than 1024px either tablet or mobile UI is used but if I then scale the window to above desktop size (for example by maximizing it) the layout changes to desktop mode but the menu bar dropdown-items are no longer displayed.
Obviously they still follow some css instructions from tablet/mobile UI and don't get their expected behaviour assigned when rearranging the layout.

the other way round (starting in desktop mode and scaling down to tablet mode) works by the way but the behaviour is still different from starting in lower res modes.

would be very appreciated if this could be fixed or if you can tell me where / how I can hotfix edit this myself.

Hi!
Could you give us the URL of your website, please. Did you try to disable the responsive design or this problem has occurred unexpectedly?

thanks for the fast reply

the url is:
http://www.oberbecks.de/volleyball/

The problem occured unexpectedly, I didn't try to disable the responsive design, quite the contrary I really really want it to work.

Oh, that is ok. Website is supposed to be displayed on one type of device. If you use desktop - it will shown in the desktop mode. If you open your website on tablet - the tablet mode will be working. Ordinary visitors of your website don't need to shrink and stretch the page again. Even if it is needed you just have to refresh the page and you are done.

indeed refreshing fixes it but... well my visitors got a bit confused.
The point is they did use a desktop browser but the window was not maximized when they opened the page but they maximized the windows basically instantly after it was loaded leaving them without the whole menu which... sucks
If that is the expected behavior that is unfortunate but thank you for the immediate support. Maybe I can find a small fix for me by myself.

You can simply disable the tablet mode or change settings for tablets. For example, you can specify another width when the teblet mode should be enabled. You can do this in the file inc --> library.php on the line:

<link rel="stylesheet" href="<?php echo get_template_directory_uri()?>/css/tablet.css" type="text/css" media="screen and (min-width:640px) and (max-width:1023px)" />