Unable to submit enqueue form

When trying to enqueue for a timeslot in this example: https://queue.tudelft.nl/lab/8884 To reproduce: Just fill in the enqueue form for a slot and click the 'enqueue' button.

The error:

initialiseState @ push.js:46
enqueue:1 An invalid form control with name='room' is not focusable. <select class=​"textfield" id=​"input-room" data-select required name=​"room">​<option selected hidden>​</option>​slot</select>​

There is no room required however the backend does expect one, I tried removing the room from the form and inserting random IDs but I do not have access to the back-end/am not an official contributor.