Steps to reproduce:

The following procedure represents the "Custom - OS - Linux - Filesystems" dashboard configured in the following template:
https://github.com/scoopex/zabbix-agent-extensions/blob/master/zabbix_templates/5.2/custom-os-linux.xml

Procedure:

1. Create a template
2. Create a autodiscovery
3. Create three types of graph prototypes for the same "thing" but different measures
4. Create a host dashboard
5. Add every of the three graph prototypes as columns and define them with Columns=1 and Rows=1
6. Assign the template to a host
7. Auto discover at least 2 "things"
8. View the dashboard
9. Unless previous zabbix releases you do not get a graph matrix with 3 columns and the number of rows of the discovered "things", you now have to page separately every graph through the graphs created by the graph prototypes

Result:

Screenshot of the described template with zabbix 4:

Screenshot of the described template with zabbix 5.2:

Expected:

• The graphs in the same line should reference the same "thing" (in my case the file system) but present the different aspects of the "thing"
• The discovered "things" (in my case the file systems) should be enumerated by the rows
• All graphs in the same row should be aligned (see ZBX-7967)