Setting index.search.slowlog.threshold.* is not working

I have around 400 indices. Some time back I enabled full logging by below command.

curl -XPUT -H 'Content-Type: application/json' 'http://localhost:9200/_all/_settings?preserve_existing=true' -d '{
"index.indexing.slowlog.threshold.index.debug" : "0s",
"index.search.slowlog.threshold.fetch.debug" : "0s",
"index.search.slowlog.threshold.query.debug" : "0s"
}'

Now I am done with collecting logs and want to disable this. So i am running command.. Just adding -1 to debug and trace both...

curl -XPUT -H 'Content-Type: application/json' 'http://localhost:9200/_all/_settings?preserve_existing=true' -d '{
"index.indexing.slowlog.threshold.index.debug" : "-1",
"index.search.slowlog.threshold.fetch.debug" : "-1",
"index.search.slowlog.threshold.query.debug" : "-1",
"index.indexing.slowlog.threshold.index.trace" : "-1",
"index.search.slowlog.threshold.fetch.trace" : "-1",
"index.search.slowlog.threshold.query.trace" : "-1"
}'

But still logs are getting generated.
from http://localhost:9200/_all/_settings, I do see still as 0 for few. and few have -1. Not sure why it is not updating all indices...

"index": {
"search": {
"slowlog": {
"threshold": {
"fetch": {
"trace": "0s",
"debug": "0s"
},
"query": {
"trace": "0s",
"debug": "0s"
}
}
}
},
"indexing": {
"slowlog": {
"threshold": {
"index": {
"trace": "0s",
"debug": "0s"
}
}
}
},

There is a huge logging happening and want to stop it...Please help on this