Yes, it all started as usual with a massive win for Brazil, but then a surprise lost match against Peru started everything. They then went to draw with Venezuela, which is arguably the weakest in the region, and then went on to lose three consecutive matches.
I don't think Brazil has ever performed this poorly at any previous qualifier.
We'll see if they can come back against Ecuador
I think this could happen because Brazil today is not the same as it used to be. Currently they only rely on Neymar. And it can be seen how they were so unprepared when Neymar was injured. When we look further, Brazil's 1-7 defeat against Germany in the world cup a few years ago was also due to Neymar being absent due to injury against Colombia (CMIIW because I can barely remember everything). This is very sad news because they brought 5 world cup stars to their country.
The problem for Brazil now is that seven to nine players from their starting XI are injured and outright sidelined. They are playing in the World Cup qualifiers with a completely new team. Despite playing with a completely new team, Brazil's performance should have been a little better. Chances are not over for Brazil, there are still many matches left and I am sure Brazil will qualify for the World Cup.