Sub-timelines not updated in main-timeline

From a city trip last week, I'm making a memories-video. During this trip, I did several activities.
The video clips are grouped per activity in dedicated sub-timelines. Then these (11) sub-timelines are put in a new main-timeline.

When reviewing the complete video, I decided to work a bit further in the sub-timelines and removed some clips there.
Going back to the main-timeline, the sub-timelines have the same length, and when playing, they have a black/empty part at the end, corresponding to the length of the removed clips.

As a result, I have to remove the sub-timeline and insert it again from the media pool. And of course also shift all the other sub-timelines. Hence, I was looking for some sort of an 'update timeline' button, which is apparently not there.

Is this the normal way of working, or did I miss something?
Thanks for any feedback.

Best Regards, Marko

Is this the normal way of working

Yes.