If the first block of your surveys differs but the structure is identical starting from the second block onward, you cannot use the standard Consolidate Reports feature directly, as it requires identical survey structures throughout. However, there is a workaround.

You can use the Merge/Consolidate Data feature to combine responses from multiple surveys by mapping identical questions starting from the second block. This allows you to consolidate (merge) data for matching questions even when the initial blocks differ.

Steps to Merge Data of identical questions in two different surveys:
1. Open your primary survey.
2. Navigate to Analytics > Consolidate Data.
3. Click + Consolidate Data to initiate the merge.
4. Select the second survey to merge.
5. The system will list matching questions from both surveys.
6. Map the identical questions you want to include in the consolidated dataset and click on Merge.

This approach lets you analyze combined data for identical questions across surveys within a single consolidated dataset, despite differences in the first block.

Please refer below help file for more details.
Consolidate / Merge Data : https://www.questionpro.com/help/consolidate-data.html