Editing "Beginning Text" field for 8va line prevents "Show numbers only" toggle from working.

Steps to reproduce issue:
1) Create an 8va line over some bars in any score.
2) Edit the text in the "Beginning Text" field in properties. It seems that any manual edit here causes the bug.
3) Attempt to use the "Show numbers only" toggle. No effect.
Reproducibility unknown, seems to happen consistently on my PC (running Ubuntu 20.04) but I don't have it installed on any other machines or OSs.