According to the docs an accordion with multi: true should be able to have all accordions collapsed. https://docs.webix.com/api__ui.accordion_multi_config.html
With collapsed: true it starts that way but after you expand one you cannot close it without opening the other.
Hello,
Sorry, but if I set multi: true everything works as well
https://snippet.webix.com/y0zq30da
There is you can collapse accordion after expanding
not a bug, but by design
false (default) - only one panel can be (and must be) visible at a time;
to achieve your goal
https://snippet.webix.com/uwxn6tyo