Existing Group Not Found Under ‘Read’ Section of Product Category. & Product and Category Mass Delete.

Hello,
I’m having some issues with Restrict Categories/Groups and would like some help..

I’m struggling with trying to figure out why my existing groups aren’t showing up in the ‘Read’ section of my product category. Only one is.. ‘Registered’. I can create new groups in the ‘quick create group and capability’ section, and then they will show up. But I already have several groups already made. Why can’t I find them here? https://www.screencast.com/t/crRdvmXA

My existing groups: https://www.screencast.com/t/peQ2H16I

In the documentation it says: “If you are going to use an existing group to restrict access to this new category, click in the field and review the list of existing groups that appears – you must be a member of a group to use it here. You can also start typing part of the name of the desired group to reduce the list of choices. Click the desired group.”

Maybe i’m not understanding the ‘must be a member of a group to use it here’ part.. am I missing something?

Second note, and possibly bigger issue.. when I did create a group with the ‘quick create group and capability’ feature and then had a group tied to that category of woocommerce products. When I later deleted that group.. it also deleted my category and all the products that were in it. I had to do a website restore to get them back. Why would it delete the category and products by just deleting the group that it was tied to?