CSM and Product Manager working relationships

Hi All,

Im hopeful someone may have a documented workflow or table that outlines the ways in which Product Managers and CSMs work both internally and with customers.

Specifically here it would be good if there was something that outlined where PMs roles stop when it comes to interacting with them? I joined a business to build CS for the first time and to date PMs have held the customer relationship. The business understands the need for CS but product still want a large role in working directly with customers.

I can put something together myself but really keen to get something from the industry that outlines industry standard rather than my opinion.

TIA