I've recently noticed that input fields or textareas on websites are not behaving as expected and they get this default Windows button sort of look. You can see what happens in the screenshots below.
The Opera version is 56.0.3051.36 and it's running on Windows 10. There are no plugins or any special addons installed in the browser and this behavior happens on any website. Since it looks kind of like a graphical glitch, it may be worth mentioning that the graphics card used is Intel HD Graphics 620. In Edge or Firefox, there is no such problem.
Do you know what the problem is and how to fix it?