I don't know if it is a cause or consequence, but it caught my attention. I don't think that the bounce rate is a factor or signal, I've TLD domains for each country, some domains are affected but not others not. The bounce rate is similar between them.
In other, with -15% down traffic, the bounce rate is very low (<23%).
I think that semantics and/or sintaxis is a crucial factor, Google could be compared between different pieces of your own website and identify redundant content, in adittion Google could use something like a spell checker.