Yes, this is a real pattern that other Customer Service Workspace customers have reported. There are community cases showing progressive memory growth, browser freezes, and eventual Out of Memory crashes, including cases where the retained objects appeared to originate from Microsoft/OOB workspace components rather than customer customizations.
Based on what you have already tested, I would classify your issue as:
Likely Customer Service Workspace/browser-runtime memory retention or performance issue, rather than a simple browser, network, hardware, or customer customization problem.
I would not claim that it is definitively a Microsoft product bug yet. The strongest next step is to demonstrate progressive heap growth and failure to release memory across repeated session open/close cycles, then use that evidence to push Microsoft Support toward investigating the OOB workspace/runtime components rather than repeatedly asking you to troubleshoot your environment.
