No one offers free LTS (or, rather, what you call "free LTS" is very different from a real LTS service, which is always paid, and you might not be getting what you think you are). The "LTS release" you get for free are builds of OpenJDK Updates. Try to open an issue on, say, Nashorn against a "free" LTS 11 and see if it gets addressed. It won't be -- unless you actually pay for a real LTS -- because Nashorn has been removed from the mainline and there's nothing to backport. Same for CMS or any other package or component that's been removed.
If you're using one of those "free LTS" distributions you should know that you're using a JDK that's not fully maintained. The only JDK version that's fully maintained completely free is the current version. To be fully safe and run maintained software you can either use the current version for free or use an old version and pay someone for LTS.
Maintaining a JDK is a lot of work. There are a couple of hundred full-time developers working on OpenJDK tip and maintaining the current release; there are ~10 full-time engineers (probably less) from all companies combined maintaining both OpenJDK 8u and 11u. For real support for an old version you must pay.
If you're using one of those "free LTS" distributions you should know that you're using a JDK that's not fully maintained. The only JDK version that's fully maintained completely free is the current version. To be fully safe and run maintained software you can either use the current version for free or use an old version and pay someone for LTS.
Maintaining a JDK is a lot of work. There are a couple of hundred full-time developers working on OpenJDK tip and maintaining the current release; there are ~10 full-time engineers (probably less) from all companies combined maintaining both OpenJDK 8u and 11u. For real support for an old version you must pay.
(I work on OpenJDK at Oracle)