Safari History won’t clear after repeated tries.

Hi Waterseeker57,

We appreciate you reaching out to us.

For accuracy, we'd like to confirm some details.

Did you use the steps below to clear the browsing history in Safari?

Clear your browsing history in Safari on Mac - Apple Support

Did you use the steps below to delete the bookmarks in Safari on your device?

Delete a bookmark in Safari on Mac - Apple Support

If you answer yes to both questions, please check if the issue persists while on safe mode.

Safe mode does a basic check of your startup disk, similar to using First Aid in Disk Utility.

Performing this step may help resolve the issue, or further isolate the issue.

Below is an article to help guide you through the process.

How to use safe mode on your Mac

If the issue persists on safe mode, please test if the issue happens on a newly created user account. 

1. "On your Mac, choose Apple menu > System Settings, then click Users & Groups  in the sidebar. (You may need to scroll down.)
2. Click the Add Account button below the list of users on the right (you may be asked to enter your password.)
3. Click the New Account pop-up menu, then choose a type of user.
4. Enter a full name for the new user. An account name is generated automatically. To use a different account name, enter it now—you can’t change it later.
5. Enter a password for the user, then enter it again to verify. Enter a password hint to help the user remember their password.
6. Click Create User."

You can use the article below as a reference.

Add a user or group on Mac

Take care!

Hi Waterseeker57,

We appreciate you following up with these details. We wouldn't want you to have to reinstall macOS again either.

While you're troubleshooting Safari, this may help you to close your tabs more efficiently since so many open at a time: Close tabs in Safari on Mac

"In the Safari app  on your Mac, do any of the following:

• Close a tab: Place the pointer over the tab in the tab bar, then click the Close button on the left side of the tab.
• Close all other tabs: Control-click the tab you want to keep open, then choose Close Other Tabs.
• Close all tabs to the right: Control-click a tab, then choose Close Tabs to the Right.

If you click a link that opens a new tab, you can close the tab by clicking the Back button ."

Since you're not able to recreate the same behavior in a new user account, you may consider troubleshooting any login items on your Mac as outlined here: Remove login items to resolve startup problems on your Mac

"On your Mac, choose Apple menu  > System Settings, click General  in the sidebar, then click Login Items on the right. (You may need to scroll down.)

Make a list of the login items in the Open at Login list—you’ll need to remember them later.

Select all of the login items, then click the Remove button .

Choose Apple menu  > Restart.

If this solves the problem, open Login Items settings again, add the login items one at a time, and restart your Mac after adding each one.

When the problem occurs again, follow the steps above to remove only the last login item you added."

If you have any extensions installed for Safari, you can also turn off extensions to help you isolate this behavior further: If Safari doesn't open a page or work as expected on your Mac - Apple Support

"Check Safari extensions

If you installed any Safari extensions, turn extensions off. From the menu bar in Safari, choose Safari > Settings (or Preferences). Click Extensions, then deselect each extension to turn it off. Learn more about Safari extensions.

If you find that an extension is causing the issue, make sure that the extension is up to date."

The resource above includes many great troubleshooting steps which may help as well.

If you're still experiencing the same behavior, you may consider reporting it to Apple directly so that they can investigate this further with you. You can find their contact details here: Contact Apple Support 

Kind regards.