I apologize for not having followed the instructions in the pinned "Instructions on posting about problems in Opera for Mac" post when I posted this topic.
I didn't see that post until now.
I am using Opera version: 104.0.4944.36 (x86_64) on MacOS 13.6.
I tried deleting and reinstalling Opera, but that didn't solve the problem.
Here are screenshots to illustrate the problem: