Modifying dynamics in Play mode

I’ve encountered the following issue several times and haven’t been able to determine the cause.

Occasionally, Dorico won’t allow me to edit dynamics in Play mode. Although the dynamics entered in the score appear correctly, I’m unable to select the corresponding automation points in Play mode or create new ones using the Draw or Line tools. I’m trying to understand what conditions might prevent these tools from working.

Dorico 6.1, macOS Tahoe 26.1