@miyukiwork
Thank you for your reply.
It is OK, the bug is not critical, rather inconvenient. I have not experienced it with Opera 60, I believe. Yes, it happens in both portrait and landscape orientation, but the essential condition when opening a link, is that Opera should not be running in background, but should be opened anew. I face the bug in two cases:

1. When I close Opera with some page displayed, and then open the browser again.
2. When I tap a link in some application and it invokes previously closed Opera and displays the content.

Version: 61
Build: 3076.56625
Android version: 9
Device: Huawei M5 Lite (JDN2-L09)

Hey, every time i open Opera anew, the butons get collapsed (see the screenshot) . It takes to open a new tab for the buttons to get properly aligned. I tried Opera Beta with no luck. Thank you.