Hey Nico,
Thanks for reaching out to us on this! I can help you getting this right…
First let me say I checked out your site and the filter bar is consistently showing (reloaded 5 times), I cannot see the glitch you are reporting. Are you still able to see it? If so please let me know which browser you are using, and also if there are any JavaScript errors in the console (here’s how to check that).
Also, I see you tested for conflicts (switched to default theme and deactivated all plugins but ours). Did you see the same error in those conditions?
Lastly, while the snippet might help here please note this should be working just with the Default State setting. At least in a default WordPress theme!
Please let me know about it,
Best,
Nico