During the 500+ Nodes Performance Test and the Testnet Update there have been problems found on the Testnet as a result of the stress test. As a consequence NEM Core Devs, NGL Test team, and NGL exec have decided to postponed Symbol Launch to February. The exact date will be announced in the coming days. Read https://forum.nem.io/t/symbol-launch-issues-update-30-12-2020/26674