https://www.windy.com/-Weather-radar-radar?radar,-26.284,-51.350,6,m:cXUaeKV

The weather radar has a trail that doesn't go out even when the weather is nice. This track is in the west/southwest region of the state of Paraná and hugs a little bit of Paraguay and Santa Catarina.
It covers the cities of Dois Vizinhos, Francisto Beltrão, Quedas do Iguaçu, Palmital, Turvo.

I believe it is a defect.

The Federal University of Parana has its own high quality weather radar that can be used.
http://www.simepar.br/prognozweb/simepar/radar_msc

Besides offering rain radar, they also offer satellite, weather forecast, hydrometric, wind speed, and lightning. The service is focused more on the states of Paraná, São Paulo, Santa Catarina, and Mato Grosso do Sul. It is worth taking a look, I believe it would be a great addition to the platform and the cost is probably zero since it is owned by a public university.