Orderby="rand" doens't work

Hi,
I’m using Listable, and try support of them, but They said there I have to ask “help” to wp_manager_job rsrs, well I hope I in the right way…

• If I use [jobs orderby=”rand” show_categories=”true” show_map=”false”], just orderby doesn’t work, other all args run perfect…What I have to do? or Where I’m wrong in this?
• When someone does a search, they are brought to the listing page with the map. I need all of the listings to come up randomized, instead of by date. This way, it will always look different and users can discover new things (it also allows the older listings to be displayed at the top sometimes as well.)”

At 2 doubt, if have a “light”/sugestion to get this – without use another plugin, I’m gratefull
Thanks

https://ww.wp.xz.cn/plugins/wp-job-manager/