Salesforce and SharePoint Customization Expert Needed

I am looking for an expert in integrating Salesforce and SharePoint. We manage SharePoint folders (create and delete) on Salesforce accounts. It worked well initially, but now it returns an error after the client updated something on their end. It seems they updated or created a new Azure app. However, the client can't share their account details due to security concerns. Can you suggest how I can help the client? I am open to a high budget if we can solve the problem.
- salesforce & sharepoint
Thank you.