There's one big project that requires involvement from different members - infrastructure, backend, frontend, security, etc.
The members are working a flavour of Scrum using Jira to keep track of the progress.
Story Points (SP) are introduced, following Fibonacci numbers and the estimates are done only by the member in charge of the User Story / Task / Sub-Task (let's call that member => task owner).
The Product Owners and Scrum Master expect the team members to deliver 5-8 SP per 2 week sprint. This can be a SP given to one or more User Stories / Tasks / Sub-Tasks.
Seven members deliver maximum 8 SP. One of the members delivers consistently 55 SP (for the third sprint now).
The Scrum Master wants to keep the burn down consistent. So, his solution is to change the 55 SP estimate to 8 SP.
The member who evaluated in 55 SP has strong opinions that justify the value of 55 SP (in light of the other existing estimates) and sees one of the following things -> he's being told to work less OR the work is being devalued.
How to proceed in this scenario?
I'm aware of this question - How should a team handle disagreements about story-point estimates in Scrum?
The difference is that the case I describe is more specific and the estimates are done only by one person - the one working on the task.