Why does this happen using google in Safari on my MacBook Pro?

See if you have unknown Profiles.

To remove a configuration profile in macOS:

1. From the Apple menu, select System Preferences....
2. From the View menu in System Preferences, select Profiles.Note:
3. Profiles won't be visible until you have at least one profile installed.
4. Select the profile you want to remove, and then press the - (minus) button. Click Remove to remove the profile.
5. softwater

User level: Level 5 (5,557 points)

Feb 16, 2020 3:04 AM in response to sukwaria

If your browser prefs are locked down, you'll probably find the reason in System Preferences > Profiles. 

Remove all profiles you don't recognize, then run something like DetectX to clear out the persistence agents. 

https://sqwarq.com/detectx/

Disclaimer: DetectX is a utility I develop; you do not need to pay for it to use it to use it. It does not collect your data or require any form of subscription/login.

Start with this...

Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode? Could take 10 minutes or more.

Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.

We need to see what all is running, a report from this will not display any personal info...

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

Pastebin is a good place to paste the whole report if you capture the URL while there…

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...

Safari in Mojave is no longer supported by Apple for security updates and bug fixes. Consider switching to another app like Firefox.