the tc string last updated date was more than 13 months ago.
I have given the complete solution of error 3.3 in this post, you should follow each and every step of this post properly.
AdSense IAB TCF Error 3.3: How to delete old string and reobtain consent | You can fix 3.3 error in just 5 minutes.
Click: Privacy and messaging
Now you click on GDPR.
You are now in the General Data Protection Regulation.
Now click on Settings.
Add purposes for your own use
Edit the Purposes selected.
If you want to change the setting of any one of these purposes, change any one to Note Use or Consent.
Store and/or access information on a device
Select basic ads
Create a personalised ads profile
Select personalised ads
Create a personalised content profile
Select personalised content
Measure ad performance
Measure content performance
Apply market research to generate audience insights
Develop and improve products
Now click on the confirm button.
In the last you will get the save button, after clicking on it you will see a message which I have given below.
Re-prompt all eligible users for consent?
You’ve changed critical settings and may want to re-prompt your users. Do you want to show your GDPR message(s) again and re-prompt eligible users for consent?
In this message, you have to click on the Re-prompt button.
Now all eligible users will see the GDPR message again. Now you have to wait for one month only after one month 3.3 error will be removed and you focus on your work now you don’t need to worry error will be removed in one month