Can't copy from pdf
Possible bug in system: I opened a pdf attachment inside Google's Inbox, while using latest version of Vivaldi. When highlighting text and copying it, the text could not be copied. When I duplicated it in Chrome, it worked.
You are correct, I was able to reproduce the bug on my Mac.
If you want, you can report this bug here and then post the issue ID in this thread. Then I can confirm the bug myself in the bug tracker and wouldn't need to ask someone else to reproduce and confirm it (the bug reporter and the confirmer always need to be two different people).