Credit Report errors like this are common
The 3 major credit bureaus are independent of each other. They do not share information, and each has its own separated report mechanism.
Many creditors report to just one or two credit bureaus, which may lead to further differences between credit reports.
Your creditor may have stopped reporting to Equifax before the account was closed, or it may be a simple honest error. Many such errors occur and can be easily corrected. All you need to do is file a dispute and the error will be fixed.
If the account is closed – file a dispute to Equifax. If it’s open, file a dispute to Experian & TransUnion.