Urgent M365 Access & Sync Fix

I need a Microsoft 365 specialist who can jump in today and get a new employee fully operational. Right now they can sign in to the tenant, but SharePoint sites refuse to load and OneDrive throws sync-error pop-ups on their Mac.

Here’s the situation:
• SharePoint Online – the user reaches the URL but the site won’t open at all; other colleagues can reach it, so I suspect a permission or group assignment gap.
• OneDrive – login succeeds, yet the desktop client on macOS instantly shows sync errors and never pulls any files down.

What I’m after is simple:
1. Correct permissions or policies so the user can open the required SharePoint site without errors.
2. Ensure OneDrive connects, sync completes, and files appear locally on their Mac (latest macOS, standard OneDrive client).
3. Document briefly what you changed so I can replicate the fix for future onboardings.

We have admin-center access (Azure AD, SharePoint Admin Center, Microsoft 365 Admin) and can hop on a remote session immediately. If you’re confident with SharePoint Online permissions, Azure AD group membership, and OneDrive troubleshooting on macOS, let’s get this wrapped up today.