Side cart not working on mobile

I got a message from a customer telling me she was unable to order online. On my laptop the process work fine. However if I try to order online on my phone the product is added to the side cart. But the side cart itself is not responding; it shows than an item is added. But by clicking the button on it nothing happens. I try to reproduce it in chrome in responsive mode it works. So I’m unable to reproduce it on an emulator. Could you please help? I have no clue when this behavior started. But as you might understand; I hope this can be resolved asap. Thank you. Marjolein

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