If you have any problem with integration of Google tracking code in Oxygen builder, I have encounter the seame problem, and it seems comment like <!-- Google tag (gtag.js) --> at the beginning of the script is not supported.
You can find the original Facebook post in Oxygen official group here : https://www.facebook.com/groups/1626639680763454/posts/6054501887977189/?comment_id=6054513334642711&reply_comment_id=6054828991277812¬if_id=1682081988211737¬if_t=group_comment_mention
So if you have install any plugin to insert code in head, body or footer on Oxygen builder, and you have problem of builder loading, you that by removing comments in Google Analytics code or Gtag code, or any other code, the bug will be fixed.
