I’m not sure if this issue is a server misconfiguration or something wrong with Microblog, but every PNG image I upload gets trashed — colors inverted, quality degraded.
An example: https://social.manualdousuario.net/o/376a57b73d59481a80f3762fd7b74e7a
Another: https://social.manualdousuario.net/o/32a9f26b637043d68a1add906e12b027
A 3rd-party library (pillow) is used to convert images to webp (to reduced page loading time), I will add a setting to enable/disable this behavior.