H1b visa transfer to previous company (P. company did not revoke H1b after I left)

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I left my previous company at Feb and they did not revoke or informed USCIS that I left.
After 6 months in new company, previous company asked me joined back and I accepted the offer. Now previous company realize they never informed USCISmy H1B in Feb. So they dont need to file H1B transfer.
Also my wife, does she need to file H4 visa transfer again. I am not sure about this situation. Do Any one has any suggestion?