@Aguarin Iriarte - Have you been setting the start view as per the following instructions?
https://help.miro.com/hc/en-us/articles/360017730813-Sharing-boards-and-inviting-collaborators#01FPSJHNC3GVMMANZDM4Q317QS
Embedding
While we’re on the subject, here’s a quick note if you end up embedding boards into websites: From a read through the How to embed editable board into website Help Center article, it looks like you can specify the start view for each embed.
https://help.miro.com/hc/en-us/articles/360016335640-How-to-embed-editable-boards-into-websites

Making a board public in share settings
Set the start area to define which part of the board will be first shown on the embed.
✏️ You can set different start views for different embeds of the same Miro board.

Settings the start area for Miro board embed