WiFi connection

Go step by step and test.

1. Empty Caches from Develop menu twice.

    Use the developer tools in the Develop menu in Safari on Mac ...

2. Remove website data;

    https://support.apple.com/en-gb/guide/safari/sfri11471/13.0/mac/10.15

3. If Safari doesn’t load website pages

    https://support.apple.com/guide/safari/if-you-cant-open-a-website-ibrw1071/mac

    If you can’t open a Safari window on Mac

4. In some cases this can happen if adware, anti-virus software or cleaner type application are installed.

    To find out, run EtreCheck and post the report here.

      https://etrecheck.com

      Click  “Free download” button,

      Open Downloads folder, click on it to open, and then select ”Open”.

      “Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.

      Click “Share Report” button in the toolbar, select “Copy report” .

      Paste the report when you reply.

5. Startup in Safe Mode:    https://support.apple.com/en-us/HT201262

    Login to your account.

    Launch Safari and test.

    To exit Safe Mode, click  in the menu bar and choose “Restart”.

Please read If your Mac doesn't connect to the Internet over Wi-Fi