Despite the apparent initial fix to character progression, server problems were still affecting players in the midst of post-launch. Users continued to report that trying to create online lobbies resulted in error messages about issues communicating with game servers. Some players even reported that they had trouble launching the game at all.
While these issues could be caused by the servers' inability to handle its large player base at launch, it certainly isn't a good look for the remaster.
In an official forum post, Blizzard Entertainment announced patch notes for Sept. 24. The patch seems to address many of the issues players have had in their first two days. The dev team has touted a "permanent fix" to things like losing character progress, but game lobby issues are still being evaluated.