Help! E-mail addresses constantly being added as new contacts!

I did some hard Googling to try and fix this a few months ago and came up empty. The only possible solution I saw was the one you mentioned, and, like you, that deleted most of my contacts so I re-enabled it. I'll have to check and see if it still does this with the iOS 18 beta.

I have a fix for you, but it requires a little work. If you are willing, this, should, fix the issue. As you may or may not know, this is/was a Google API bug. It has reportedly been fixed, but pretty much anyone who uses Google (see: Every body) will likely end up dealing with this at some point.

Anyway, here are the steps:

1. Go to Settings > Mail > Accounts. Tap that.
2. Find your Google account, tap this, then uncheck Contacts. You may or may not be asked to delete all of the contacts. Do this. It is important as really all you are doing is disabling Google Contact syncing.
3. Open your Contacts app, not the Contacts tab in your phone app, but your, actual, Contacts app.
4. You should be presented with a screen with all of your "Lists". You can do a few things here, but you want to merge contacts first. So swipe around the screen until you find 2 buttons; Merge All or Ignore All. You want to tap Merge All.
5. If you noticed when you first opened the Contacts app, each "List" had a number besides it. This is the number of contacts that particular list has; when you merge contacts, those numbers change. Not necessarily important, but just giving you a heads up.
6. Once the merge is complete, swipe to your Google list, swipe up or down, and delete. Don't question this.
7. You should be presented with 1 or possibly 2 lists; iCloud and maybe Card, as in Sim Card. Keep or delete the Sim Card contacts. It is entirely your call.
8. Go back to Settings > Mail > Accounts > Google, tap that.
9. Re-check Contacts to enable syncing again.
10. Reboot or power cycle your device.
11. Praise Brian as being the king of obscure iPhone tips & tricks. Important step! 😉

This, should, fix the issue.

Sorry, I know there are a lot of steps, but this is the only way I have found to fix this situation. 🤷