No, that's as expected! LTSC still gets updated, but only for security issues—they will never change anything else.
That means the updates are smaller and less frequent, and rarely break anything. Personally, this is exactly what I want.
There are registry keys which will fully turn off automatic updates, if you want. I use these in Virtual Machines, since I don't boot those frequently and they're supposed to be disposable. I'm pretty sure they also work in Enterprise and Pro, btw.
For what it's worth one of LTSC updates dropped the display frame rate to 5 fps until the machine was rebooted and another spawned a temporary process that started eating 80% of CPU. Both happened in a span of just several months.
That means the updates are smaller and less frequent, and rarely break anything. Personally, this is exactly what I want.
There are registry keys which will fully turn off automatic updates, if you want. I use these in Virtual Machines, since I don't boot those frequently and they're supposed to be disposable. I'm pretty sure they also work in Enterprise and Pro, btw.