This might be a quick fix in MQTTConnector.js, but I am not sure if we can just change value_template with position_topic.
Warning from Home Assistant:
Logger: homeassistant.components.mqtt.cover
Source: components/mqtt/cover.py:130
Integration: MQTT (documentation, issues)
First occurred: 07:45:23 (2 occurrences)
Last logged: 07:45:23
using 'value_template' for 'position_topic' is deprecated and will be removed from Home Assistant in version 2021.6, please replace it with 'position_template'
This might be a quick fix in MQTTConnector.js, but I am not sure if we can just change
value_templatewithposition_topic.Warning from Home Assistant: