Hi all, How bad is it to have a link in the breadcrumb that 301 redirects? We had to create some hidden category pages in our ecommerce platform bigcommerce to create a display on our category pages in a certain format. Though whilst the category page was set to not visable in bigcommerce admin the URL still showed in the live site bread crumb. SO, we set a 301 redirect on it so it didnt produce a 404. However we have lost a lot of SEO ground the past few months.  could this be why? is it bad to have a 301 redirect in the breadrcrumb.

Due to Poor unsightly look of breadcrumbs and the space it takes up above the fold we only employ breadcrumbs on our desktop version. Breadcrumbs are hidden from view on mobile version. However as mobile first indexing is now in play what technical SEO impacts will this have?    one thing that comes to mind is crawling deeper pages where breadcrumbs made them accessible in less than 3 link clicks?  But i am unsure now of the impacts of not having breadcrumbs visible for mobile version of our site.