Every Friday the Czech government reviews the list of countries with a low risk of infection with the corona virus. Germany has been on the list since last week, but this is no longer the case as of November 16.
The real effects are small. For foreigners, the necessity of an important reason for entry continued to apply. Only for those who had one, the procedure will now be more complex ( compulsory quarantine and testing).
You can find the details under Current Corona Rules in Saxony and Czech Republic.