I saw a post from 2014 with the same issue and no resolution.
I'm hoping someone has a work around for this.
I use the mac OS TTS shortcut for everything (Highlight text, then option+ESC) to proofread emails, papers, and other important documents I'm writing.
When using it on Opera, It only ever reads the tab names.
In the grand scheme of things, I can always just use chrome or open a sticky note and copy and paste things to proofread from there, but I would love Opera to be my main browser on all devices. This is the only real downfall I've stumbled upon. It's just sadly a huge issue for me.
I followed the normal trouble shooting steps: tried this on multiple websites, reset to factory settings, made sure to turn off ad blocker, vpn, antivirus, and the works.
Anyone know a solution?