Diablo II Resurrected was updated by Activision to version 1.003 today. You can find out the complete patch notes for this update from here.
This update resolves an issue with the offline characters not saving when they had the same name as the online characters. Other issues that were fixed including one that was linked to the Xbox Live accounts, and more. The PC version was also updated to resolve some issues with the game. You can find out the patch notes below, or see them on the official website.
Diablo II Resurrected Update 1.003 Patch Notes
Here are the PC patch notes.