A solution how to get the last modified sites?

Hello, maybe someone has a hint. What is the best way the get the last modified SharePoint Online sites? 

I know the Graph-APIs...

• Search for sites https://docs.microsoft.com/en-us/graph/api/site-search 
• Get site https://docs.microsoft.com/en-us/graph/api/site-get 

Both APIs have a lastModifiedDateTime property in the response. Unfortunately the 1st API, Search for site has an issue, the  lastModifiedDateTime property is outdated. The 2nd API, Get site includes the correct date/time, but an information of the site (like the ID) is required. 

In May I opened a case to report the issue and it was confirmed, also by a product team. In their answer they told me the solution is too complex, they have no ETA until when a fix is implemented. I recently checked the beta API, still the same issue.

For me it's a problem how to get the recent modified sites if the 1st API has outdated data, instead to check all sites. Is there an alternative solution? 

Best regards

Tobias