After have done the steps above and confirmed that the problem is, most probably, in Opera, it's time to post about it.

Read the rules: https://forums.opera.com/rules

Start the topic with a title that briefly describe the problem so people will know about what this is about.
Don't try to explain all the problem in the title.
Try to be as more specific as possible. Avoid too generic topic titles.

Use tags to make it easy for other users to find posts about similar issues. If posting about Opera Mail then add the 'Opera Mail' tag
Try to use up to 3 tags.

In the post (body) you should include the following information:

• Your version of Windows

• Your version of Opera

• If the problem is with a page, a link to it

• A screen-shot of the problem if it's related to something not showing as should

• A description of the problem, including as much as information as possible

• Steps to (try to) reproduce the issue

• Expected behavior and actual one

Do not use caps on your post. There aren't and there never will be reasons to use caps.

First of all you should check if the problem is not being caused by an extension or a broken profile. Do the following required steps, re-starting Opera after each one of them and checking if the problem remains after each one.

• Disable all extensions

• Disable the ad-blocker/tracker blocker

• Reset settings to default (Do a backup and export your passwords first)

• Reset flags to default

• Create a clean profile folder/directory

• Temporarily disable antivirus, firewall, anti-malware and all related software in your system

• If the problem is with a web page, check if it works with other browsers. Try checking with other Chromium based browsers

• Check if your Windows is up to date