Please try this suggestion to resolve the issue if you cannot see the correct cursor size ( or brush size in Photoshop ) on the Windows device you connect from.
Please first make sure you're running Splashtop Business app V184.108.40.206 or later.
1. Open Regedit on the remote PC you connect FROM. Press Win+R and type regedit
2. Navigate to the following path: Computer\HKEY_CURRENT_USER\Software\Splashtop Inc.\Splashtop Remote Client for STB
3. Right-click on an empty field and click New > DWORD-Value (32-bit)
4. Name it EnableScaleRemoteCursor
5. Double-click on it and ensure the Value is set to 0:
6. Press OK and restart the remote session.
If the issue persists or there are any side effects after adding the registry, please Submit a Ticket.