I checked with your scenario. I can't find the problem. Sales team respective person will automatically added to follower list. Please provide some screenshots, Then it will be easier. [Please check the same by changing  "see own leads" to "see all leads" from user settings]

Hi Nilmar.

Thank you so much for your answer. 

User got access to all leads. (also settings/ admin rights, not admin user)Another thing is that if I create a new quote and use a Quotation template, Admin is always set as sales person. I do not know if that is related, but might be worth mentioning.

Not quite sure what you want to see.

//Alexander