@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