I just discovered a bug. I use boolean arrays to report alarms, and the alarm text is linked to a string array. A quick detail: these two arrays are tags derived from a "Document"-type source in the PLC (S7-1500, communicating via OPC UA).
However, every now and then, the alarm text no longer matches the correct index.
Strangely enough, restarting the tag by clicking the "Restart Tag" button in the Designer fixes the issue.
This phenomenon occurs when communication with the PLC is lost or when the PLC is reloaded.
After analyzing the situation, I realized the issue stems from the fact that the source tag's "tag group" differs from that of the derived tags.
If I move all the tags to the same tag group, the problem goes away! Like this one:
This allows me to resolve the issue. I am sharing my findings anyway because I know the Inductive Automation teams are responsive and attentive to developers. Plus, it might help someone else facing the same problem