Travel back to USA on H-1B visa with old employer and new H-1B approval notice I-797

Currently I do have visa expiring on 9/30/2021 with old employer. I transferred my H1B to new employer starting from 8/19/2020 to 8/18/2023. Can I travel and return to the U.S. using current H-1B visa with old employer and new H-1B approval notice I-797?

Yes, you can. I recently did that and I was in the same situation as you are in. There was no issues while re-entering US.

did u have i797A or B from your new employer? and also did u show old stamping and new i797 at the port of entry? and did they ask u for any other documents?

is your new employer i797 is A or B?

I have I-797A from my new employer. Yes, showed both the old stamping and I-797 doc. No, for me they did not ask any other documents.