As of just 2 days ago, there was a critical bug that knocked the Medalla testnet offline for 90 minutes. The tweet thread below does a wonderful job of explaining what took place. The developers are still looking for answers.
ETH Phase 0 When?
While it’s a good thing this bug occurred within a test environment, it begs the question – How close are we to phase 0 of the ETH 2.0 network launching? The more bugs we see like this, the longer it’s going to take. At this current moment, people are speculating phase 0 will be released in November of 2020. The other phases of the ETH 2.0 launch could come at a much later time. Keep in mind, phase 0 is not where scaling solutions come into play.