Labels to split recording into separate tracks - Any way to fix the label to a precise point in the audio?

I am using Audacity version 2.1.0 on a Macbook with OS Sierra 10.12.6

I followed the following instructions in the Audacity manual to label the tracks in a long bit of recording:

The audio has to have very precise lengths of silence which I have edited into the recorded speech.

This has all gone smoothly. I’ve edited the audio and marked the start of each track using a label. However, now I realise I have made a handful of mistakes in my edits and need to make some further edits to the audio.

The problem that I am having is that the labels don’t seem to be fixed to the point in the audio I created them at, so any edits I make are shifting all the labels out of sync. It is extremely fiddly dragging the label back to align with the bit of audio it needs to be at and I am sure there will be a better way but I’ve done lots of Googling and reading the manual and I’m not getting anywhere.

Can anyone help? I’d be really grateful for any pointers at all.

The current version of Audacity is 2.3.2 and it is available via the Audacity website: Audacity ® | Download for Mac OS

To make the labels move in synch with edits to the audio, enable “Synch-Lock”.
If you want the labels to remain at the same “time” positions, turn Synch-Lock off.
See: Sync-Locked Track Groups - Audacity Manual
(note that this manual is for Audacity 2.3.2)