Hi, our enterprise has 5 different platinium subscriptions, and whe are having a problem with logstash, it is posible to open a case? or the support its only for Elasticsearch?
The support is about the whole stack AFAIK.
Absolutely this is possible, depending on where your it is you need support within logstash
they can provide a level of help. (for example a community plugin might be best effort where as 100% elastic stuff is 100% supported)
I do believe logstash is only under "self managed" as it is not part of the cloud but you can then select the correct option:

Goodluck