Slowness opening Test Execution page

Description
When opening a Test Execution page, the page takes too long to open.

How to reproduce

1. Create a project and add Test Run custom fields
2. Create a test execution and add more than 50 tests to it
3. Open the Test execution page

Actual result/Attachments
The page takes too long to open. Sometimes takes more than 20s to load.

Expected result

The page should load faster.