Multisite issues, only one works Sanity check failed

[briavers]

I have set it up on a wordpress multisite, but it only fully works on the website I last saved the settings (most images are converted and show properly but not all)

so there are 3 sites in this multi-site

• website.be
• two.website.be
• three.website.be

When I go to the multisite setting of one (eg two.website.be/wordpress/wp-admin/network/settings.php?page=webp_express_settings_page) and save it, it works for two.website.be but not the other sites,
if I save it on three.website.be it works there but not on the others

The error certain images have is “Sanity check failed for destination path: String expected” because a bool is passed instead of a string when it tries to show an original .jpg. When I add a ?dontreplace to the request the image show correctly.

Any help with this would be highly appreciated.