Try using the host network explicitly.

Config/Nextcloud/docker-compose.yml

@@ -21,12 +21,16 @@ services:
       - MYSQL_ROOT_PASSWORD=$MYSQL_ROOT_PASSWORD
       - MYSQL_USER=$MYSQL_USER
       - MYSQL_PASSWORD=$MYSQL_PASSWORD
+    networks:
+      hostnet: {}
 
   redis:
     container_name: nc-redis
     image: redis
     restart: always
     command: redis-server --requirepass $REDIS_HOST_PASSWORD
+    networks:
+      hostnet: {}
 
   app:
     container_name: nc-app
@@ -49,3 +53,10 @@ services:
       - REDIS_HOST_PASSWORD=$REDIS_HOST_PASSWORD
     #dns:
     #  - $DNS
+    networks:
+      hostnet: {}
+
+networks:
+  hostnet:
+    external: true
+    name: host

Config/OnlyOffice/docker-compose.yml

@@ -15,3 +15,10 @@ services:
       - JWT_SECRET=$JWT_SECRET
     #dns:
     #  - $DNS
+    networks:
+      hostnet: {}
+
+networks:
+  hostnet:
+    external: true
+    name: host