Hello,

Sometimes, the server may have been corrupted, or overload problems may occur because frequent usage and high traffic. Other significant problems, such as browser compatibility, virus invasion, outdated PDF apps, insufficient storage, even network instability ,may cause interference. So make sure to check all these discrepancies.

So what you can do,

• Clearing cache from time to time.
• Disable unnncessary extensions.
• Better to use in private or incognito mode
• Update pdf reader apps.
• Switch using the browsers from time to time.
• Verify the site source legal/or not and file permissions too.

Hope it helps with your query.