hallo @Ulknudel wilkommen im Forum 
ich würde erst mal mit occ db:add-missing-columns, occ db:add-missing-indices oder occ upgrade versuchen, eventuell ist das upgrade nicht vollständig gelaufen.
https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/occ_command.html
ich kann nicht sagen wie das beim linuxserverio image aufgerufen wird bitte schaue die docs an linuxserver.io Nextcloud docs bzw wende dich an linuxserver.io Support
zur not kannst du dieses commit anschauen, dort wird die Tabelle erstellt. bzw hier meine Tabelle (postgres - psql -d nextcloud -U nextcloud -c '\d oc_schedulingobjects'):
Table "public.oc_schedulingobjects"
Column | Type | Collation | Nullable | Default
--------------+------------------------+-----------+----------+--------------------------------------------------
id | bigint | | not null | nextval('oc_schedulingobjects_id_seq'::regclass)
principaluri | character varying(255) | | | NULL::character varying
calendardata | bytea | | |
uri | character varying(255) | | | NULL::character varying
lastmodified | integer | | |
etag | character varying(32) | | | NULL::character varying
size | bigint | | not null |
Indexes:
"oc_schedulingobjects_pkey" PRIMARY KEY, btree (id)
"schedulobj_lastmodified_idx" btree (lastmodified)
"schedulobj_principuri_index" btree (principaluri)
bzw pg_dump (pgdump -d nextcloud -U nextcloud --schema-only --table=oc_schedulingobjects) dieser Tabelle:
pg_dump / oc_schedulingobjects
--
-- PostgreSQL database dump
--
-- Dumped from database version 15.7 (Debian 15.7-1.pgdg120+1)
-- Dumped by pg_dump version 15.7 (Debian 15.7-1.pgdg120+1)
SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SELECT pg_catalog.set_config('search_path', '', false);
SET check_function_bodies = false;
SET xmloption = content;
SET client_min_messages = warning;
SET row_security = off;
SET default_tablespace = '';
SET default_table_access_method = heap;
--
-- Name: oc_schedulingobjects; Type: TABLE; Schema: public; Owner: nextcloud
--
CREATE TABLE public.oc_schedulingobjects (
id bigint NOT NULL,
principaluri character varying(255) DEFAULT NULL::character varying,
calendardata bytea,
uri character varying(255) DEFAULT NULL::character varying,
lastmodified integer,
etag character varying(32) DEFAULT NULL::character varying,
size bigint NOT NULL
);
ALTER TABLE public.oc_schedulingobjects OWNER TO nextcloud;
--
-- Name: oc_schedulingobjects_id_seq; Type: SEQUENCE; Schema: public; Owner: nextcloud
--
CREATE SEQUENCE public.oc_schedulingobjects_id_seq
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
ALTER TABLE public.oc_schedulingobjects_id_seq OWNER TO nextcloud;
--
-- Name: oc_schedulingobjects_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: nextcloud
--
ALTER SEQUENCE public.oc_schedulingobjects_id_seq OWNED BY public.oc_schedulingobjects.id;
--
-- Name: oc_schedulingobjects id; Type: DEFAULT; Schema: public; Owner: nextcloud
--
ALTER TABLE ONLY public.oc_schedulingobjects ALTER COLUMN id SET DEFAULT nextval('public.oc_schedulingobjects_id_seq'::regclass);
--
-- Name: oc_schedulingobjects oc_schedulingobjects_pkey; Type: CONSTRAINT; Schema: public; Owner: nextcloud
--
ALTER TABLE ONLY public.oc_schedulingobjects
ADD CONSTRAINT oc_schedulingobjects_pkey PRIMARY KEY (id);
--
-- Name: schedulobj_lastmodified_idx; Type: INDEX; Schema: public; Owner: nextcloud
--
CREATE INDEX schedulobj_lastmodified_idx ON public.oc_schedulingobjects USING btree (lastmodified);
--
-- Name: schedulobj_principuri_index; Type: INDEX; Schema: public; Owner: nextcloud
--
CREATE INDEX schedulobj_principuri_index ON public.oc_schedulingobjects USING btree (principaluri);
--
-- PostgreSQL database dump complete
--