Hello guys!
I was working on a project where I had multichannel outputs. So, I decided to use hierarchical Alitum project where I could easily repeat the output blocks.
One of my subcircuits I had to split in three sheets for organization and readability.
As the three sheets were about the same subcircuit I used offsheet connectors.
This way I could mantaing the horizontal connection between the sheets of the subcircuit.
The problem was that I got a lot of compiling errors and I was very hard to debug. I lost more than one day reading about offsheet connection and didn`t understand what was happing.
So, I dicovered in some forum that on a hierarchical project the offsheet connectios get connected only if on the top sheet you instantiete all related sheet separated by comma on a single block, like the image below.

All the sheets separated by comma can be connected horizontaly with offsheet connectors.
Why this is so poorly documented on altium documentation?
I quickly browsed now and could not even find where I discovered this.