Hello jonasobo,
To help us get a better understanding of the issue, we’d like to ask a few questions.
1. Does this seem to happen randomly, or does it occur after making a certain change, or completing a certain task on your Mac?
2. Do you receive any errors or messages before the name changes? If so, what does the error or message say?
Please also check out this link to ensure the correct process is being used to change your computer’s name, so we can make sure the name is being saved correctly: Change your computer’s name or local hostname on Mac
Change your computer’s name
You can view and change your computer’s name in the About settings window.
1. On your Mac, choose Apple menu
> System Settings, click General
in the sidebar, then click About on the right. (You may need to scroll down.)
2. Type a new name in the Name field.
Thanks!