There is NO evidence that Nurofen etc. will cause symptoms to worsen: logically, why would it? I did a google, like you do ;-)
Veran's tweet was widely shared, particularly in France, and the advice has raised questions over the impact of ibuprofen to treat the virus. CNN has contacted the French health ministry for comment.
"Deeply concerned about this bold statement," Muge Cevik, a researcher at the University of St Andrews Infection and Global Health Division, said on Twitter. "There's no scientific evidence I am aware of that ibuprofen [causes worse] outcomes in #COVID19."
"I don't think we've had any firm evidence to suggest that [ibuprofen aggravating Covid-19] is a concern at this point," said Dr. Yvonne Maldonado, professor of pediatrics and infectious disease epidemiologist at Stanford University in California
I can find no record of how Nurofen etc. makes 'flu etc. worse. Maybe this is being pushed by the companies that manufacture Paracetamol?