Good afternoon.
Three blogs that I installed the GPP the menu changes the behavior to a “list” unconfiguring the entire page.
The explanations found on the forum were not enough to resolve in my case.
Here is a link to the image of just one example, but they are all like this:
https://igvida.net/wp-content/uploads/2020/06/Captura-de-Tela-2020-06-09-às-15.19.35.jpg
NOTE: Tested in Firefox and Chrome, but it is not every time I try to upload that this problem generates. I have also cleared the cache (WP Fastest Cache) which corrects it temporarily, but accessing it again gives the error.
Wait.