H1 and F1 visa approved simultaneously

[Hina]

My husband got laid off in march, so he applied for F1 COS in april. In may he got another job while F1 application was in process. Now his new employer filed his H1 and with premium processing, its reciept came through. As he was going to withdraw the application he saw that his F1 is also approved on the date later than his H1 approval. Please advice how to continue the job?

[wiweq]

"As he was going to withdraw the application he saw that his F1 is also approved on the date later than his H1 approval."

=> Search for last action rule and learn more. In my view, he is now in F1 status. He should file COS to H1b and meanwhile he should stop working and maintain F1 status until the COS is approved.

One more thing switching H1b to F1 to H1b without completing the course will bite him during GC processing. This clearly shows his intent to stay in USA not studying. He would have okay if he would have opted B visa.

[Hina]

Does that mean another fresh H1 to be filed?

[wiweq]

"Does that mean another fresh H1 to be filed?"

=> Yes, or reenter in USA using H1b visa.