The software portal takes a long time to load in version 8.5 of Software Management. If you scroll through the available software, it can take a long time to render more available software.
ITMS 8.5
This is a known issue.
First, check this KB to ensure it is not a commonly known configuration issue: In a Trusted Domain Environment the Software Portal does not work properly in Software Management
This issue is fixed in 8.5 RU3. If you are using 8.5 RU2, you can use the attached revised stored procedure to resolve the issue.