I believe I figured out why my exosuits kept disappearing. I use the clear floor tool a lot because I sandbox a bunch of stuff and don't want duplicants to keep storing useless materials. However, I've discovered that using the sweep tool (sandbox mode) will delete exosuits worn by duplicants. They will still believe that they are wearing a suit and will ignore all docks. Unsure if it works with the debug tool clear floor or other worn items.
Steps to Reproduce
Use the sandbox mode clear floor tool on a duplicant with an exosuit.
This issue has not been confirmed by a developer yet.