Baseless speculation; no evidence given. Consistent with earlier pro-Kremlin disinformation message that the Schengen zone has collapsed and more broadly, with the disinformation narrative that the EU is disintegrating as a result of the coronavirus crisis.
The Schengen border code provides Member States with the capability of temporarily reintroducing border control at the internal borders in the event that a serious threat to public policy or internal security has been established:
Where there is a serious threat to public policy or internal security, these countries may exceptionally reintroduce border controls at its internal borders for a period of no more than 30 days (possible to prolong under conditions established by the code) or for the foreseeable duration of the serious threat. This action should be seen as a last resort. If such controls are to be reintroduced, the other EU countries that are part of the Schengen area and the European Commission must be notified without delay with a view to possible consultations. The European Parliament and the Council must be informed at the same time.
The European Union is supporting Member States in addressing the crisis and has adopted measures to mitigate the economic consequences of the COVID-19 pandemic. To cushion the blow to people’s livelihoods and the economy, the European Commission has adopted a comprehensive economic response to the outbreak, applied the full flexibility of the EU fiscal rules, has revised its State Aid rules and proposed to set up a EUR 37 billion Coronavirus Response Investment Initiative to provide liquidity to small businesses and the health care sector.
To support scientific research into COVID-19, the European Commission earmarked 47.5 million EUR for shortlisted research projects that can improve epidemiology and public health, including preparedness and response to outbreaks. The EU has also created first ever stockpile of medical equipment.
Read more about the EU's response here and here. For similar cases, see here, here, and here.