if you're not community banned you might still be instance banned on the community instance, which wouldn't show up in your local instances modlog if the ban happened on a <0.19.4 instance. if the methods pointed out by other comments here fail I suggest you visit the instance of the community and check the site modlog there, searching for your user.
i suspect you're referring to your post to a lemmy.ml community and you have indeed been instance banned there for a limited amount of time.
this is probably somehow related to changes introduced somewhere in 0.19.4, I've been seeing this for months at this point, as we've been on a 0.19.4 pre-release relatively early due to done federation issues