Is it really desirable behavior of pinned tabs?

I guess it depends on how you see things. Some people think that pinned tabs should remain there no matter your browser's startup settings, others may think that if the browser had been set up to start with no tabs then pinned tabs should not break it.
Some people may have different pinned tabs for each session, others may have always the same ones.
There are lots of options and it's not easy for Opera to please everyone.

Thanks for your reply! I agree with you, different people may have different opinions. But I think it is not that difficult to implement ability to configure behaviour of pinned tabs: it could be something like a checkbox in Settings menu "Save pinned tabs upon exit", and lots of people would be really happy about it! I think it is very important, because many other users, who leave other browsers and start using Opera may encounter misunderstanding, something like ("It works not like I expect it to work, it worked in different way in my previous browser, and I can not even configure that!") I really love Opera, it is one of the most comfortable browsers I've ever used, and I just want to make it even better. Thanks again for your reply!

This is a big issue for me. I prefer for pinned tabs to stay pinned between sessions.
Google Chrome has the same issue which makes me think it's an underlying issue with Chromium in general.

I have no the same issue in Chrome. For my "On startup" options I have "Open the new tab page" checked, and all mine pinned tabs are saved between sessions, the same I have in Maxthon. This makes me even more surprised, because they are not saved for Opera.

@PeterBurton , if you require any additional information, I will send it to you. Thank you.

@PeterBurton Yesterday I updated Opera on my work station and have just updated it on my home computer to the latest version LVL 1 (core: 62.0.3331.105)
The problem is same.
Can send you more info, if required, the problem is 100 percent reproducable.

Addition, the same window can be accessed if you use this link:
opera://extensions/shortcuts

There are a lot of different extensions, which have hotkey configuration. For example, https://chrome.google.com/webstore/search/yandex hotkeys?hl=en&_category=extensions
It can be installed to Opera using "Install Chrome Extensions" addon from Opera Addons.
Such extensions usually have button, which allows redirect to hotkeys' configuration page:

And in Opera GX this page is looking very odd:

Moreover, if I try to edit any hotkey (press any textbox) Opera GX will just shutdown/crash.

My Opera GX verions LVL 1 (core: 62.0.3331.52)
Windows 10 x64 1903

That would be just great! I think, a lot of people would like to have such function!

New sidebar feature is just awesome! It already has a wide range of extensions, and I think it will become greater and greater with time.

I think it would be just nice, if there was a possibility to move extensions' buttons from the top right side of the screen (after search bar) to the sidebar. I use a lot of different extensions, and with each new extension search bar becomes shorter and shorter. Sidebar could elegantly resolve this issue!

This is a big issue for me. I prefer for pinned tabs to stay pinned between sessions.
Google Chrome has the same issue which makes me think it's an underlying issue with Chromium in general.

I have no the same issue in Chrome. For my "On startup" options I have "Open the new tab page" checked, and all mine pinned tabs are saved between sessions, the same I have in Maxthon. This makes me even more surprised, because they are not saved for Opera.

Is it really desirable behavior of pinned tabs?

I guess it depends on how you see things. Some people think that pinned tabs should remain there no matter your browser's startup settings, others may think that if the browser had been set up to start with no tabs then pinned tabs should not break it.
Some people may have different pinned tabs for each session, others may have always the same ones.
There are lots of options and it's not easy for Opera to please everyone.

Thanks for your reply! I agree with you, different people may have different opinions. But I think it is not that difficult to implement ability to configure behaviour of pinned tabs: it could be something like a checkbox in Settings menu "Save pinned tabs upon exit", and lots of people would be really happy about it! I think it is very important, because many other users, who leave other browsers and start using Opera may encounter misunderstanding, something like ("It works not like I expect it to work, it worked in different way in my previous browser, and I can not even configure that!") I really love Opera, it is one of the most comfortable browsers I've ever used, and I just want to make it even better. Thanks again for your reply!

Hello!

I think, something is wrong with pinned tabs' behavior: they are not saved, when I close browser and open it again (I use option to open start page upon opening Opera, not keeping previous session). Is it really desirable behavior of pinned tabs? In most other browsers, pinned tabs are not closed under no circumstances, and in order to close them you need to unpin them and then move on.

Thank you!

Hello!

I think, something is wrong with pinned tabs' behavior: they are not saved, when I close browser and open it again (I use option to open start page upon opening Opera, not keeping previous session). Is it really desirable behavior of pinned tabs? In most other browsers, pinned tabs are not closed under no circumstances, and in order to close them you need to unpin them and then move on.

Thank you!