I own a piece of a business and provide services to it, through my sole proprietorship. Pretty much all of that business for the sole proprietorship is performing services for that business I own a piece of.
This type of situation arises all the time, usually through a professional. The problem is when that sole proprietorship has a retirement plan and that affiliated business does not or has a retirement plan with lesser benefits.
If you have a situation like this, you might have an affiliated service group issue, and it’s advisable to contact someone like me. You might have a retirement plan coverage issue.