Help: Missing Page Builder tab

Hello there,

I have found the Page Builder tab is missing on all pages and posts this morning. To fix this problem, I have tried the following steps but not working:

1. I have deactivated all plugins and see if that tab is back, but it is not.
2. I have checked all updates are completed.
3. I have clicked into “setting” and ensured Page Builder is enabled for pages and posts, but the problem is still unsolved.

I am not familiar with coding and Page Builder has helped a lot in the past. Any one can suggest what’s wrong and how to fix the issue?

Thank you very much.

best,
Liz