@Christoph Hoffmann - I’m just guessing that you are referring to the Miro interface navigation icons and if so, if you are in a browser, you could check to see what you browser zoom level is at:

If I got any of that wrong or if the above suggestion doesn’t help, please provide more details, e.g.:

• Are you using Miro in a browser or app (if so, desktop, mobile, tablet, etc.)
• Are you on Mac or Windows?
• Are you referring to the Miro interface or objects on a board?