It is normal for a site to have problems. Even the most experienced sites can still run into problems. What was the main problem in the beginning is that players have not been paid out or that there were other problems with paying players. That's the most important thing about a site. I think they underestimated the project, or hired too few software testers to thoroughly test the platform first.
In my opinion, what happened was not because they underestimated, but it was very possible that they didn't have a competent development team in their field so that the launch didn't go smoothly, moreover they didn't anticipate the abuse of bonuses so that everything looked so very chaotic. Wait for May 28, maybe there will be another delay but if this happens it's very unfortunate.