First of all, I apologize for my absence over the past month. Come the new year, I will be regularly responding to support forum requests.
As for your question. There is no need to deactivate any plugins. To set the number of posts you would like to show on your homepage simply click the ‘Gear Icon’ next to your home template tab to bring up the template options page. The image below shows where this icon is located:

After the pop-up displays, click on the ‘WP-Loop’ tab and enter whatever number of posts you would like to show. The image below shows this option:

Finally, save your template and your page will show the number of posts you chose.