Update to stopwords not reflected in Tag Cloud

My index uses a stop words file as part of its analyzer:

"analysis": {
	"filter": {
		"stopwords_filter": {
			"ignore_case": "true",
			"type": "stop",
			"stopwords_path": "en_complete.txt"
		}
	},
	"analyzer": {
		"custom_stopwords": {
			"filter": [
				"stopwords_filter"
			],
			"tokenizer": "standard"
		}
	}
}

If I want to update the en_complete.txt file to include the word "apple" then after the update I have to close and open my index. After that, searching for a stop word e.g. subtitle_text_stop : "apple" will not return any results in the Discover section of Kibana.

However a previously created Tag Cloud still shows the word "apple". To update the Tag Cloud I have to delete and recreate the index.

Is this normal behaviour or am I doing something wrong?