Hi there,
I am having similar issue as found in this post: https://support.box.com/hc/en-us/community/posts/6039339145747-Box-Folders-Missing-?input_string=missing%20folder%20via%20box%20sync%20and%20online
Is it possible to be connected with product support?
This folder syncing appeared to be working over the last six months but I cannot find this folder online anymore and now it has the red icon in my box sync.
I think it may have been a collaborative folder that someone else owned, but I am not positive.
Thank you for any help!