Cache enabler set ok but warning in Webp Express

In WebP Express Settings I get this message:

“You are using Cache Enabler, but have not enabled the webp option, so Cache Enabler is not operating with a separate cache for webp-enabled browsers.”

Cache enables is ste correctly with separate cache for webp-enabled.

the only strange thing I found is a “conflict” with autotomize plugin in the table wp_option
inside the field “uninstall_plugins”. both autotomize and WebP use the same s:29 index

a:7:{
s:27:”autoptimize/autoptimize.php”;
s:29:”autoptimizeMain::on_uninstall”;
s:29:”webp-express/webp-express.php”;
…
}