Previous employer h1b denied, any negative impact?

I just got a denial for I129 for my old h1b extension from 2016 with my old employer.
I am not sure about the reason for this denier and its impact on me?

I was on h1b with

Employer a from 2014 to 2018
Employer b from 2018 to 2020
Employer c from 2020 to till date.

I have approved h1b till 2023 with employer c.

Recently I got a USCIS notification for my old h1b extension with an employer a which was filed in June 2016, I got two notification today:

Your Case Status: Decision

On February 10, 2021, we denied your Form I129, PETITION FOR A NONIMMIGRANT WORKER, Receipt Number

Your Case Status: Initial Review

On February 10, 2021, the Post Office returned a notice we sent you for your Form I129, PETITION FOR A NONIMMIGRANT WORKER, Receipt Number

Here is the history of this case:

02/10/2021: The Post Office returned a notice we sent you for your Form I-129, Petition for a Nonimmigrant Worker because they could not deliver it.

01/27/2021: We automatically revoked your Form I-129, Petition for a Nonimmigrant Worker.

01/22/2021: Your Form I-129, Petition for a Nonimmigrant Worker, was transferred to another office for processing.

01/22/2021: We transferred your Form I-129, Petition for a Nonimmigrant Worker, to another USCIS office that now has jurisdiction over your case.

10/24/2018: We received your correspondence for Form I-129, Petition for a Nonimmigrant Worker.

04/04/2017: We approved your Form I-129, Petition for a Nonimmigrant Worker.

04/04/2017: We approved your Form I-129, Petition for a Nonimmigrant Worker, and emailed you an approval notice.

03/22/2017: We received your Form I-129, Petition for a Nonimmigrant Worker, and mailed you a receipt notice. It is being processed at our Vermont Service Center location.

02/13/2017: We mailed a request for additional evidence for your Form I-129, Petition for a Nonimmigrant Worker.

06/08/2016
We received your Form I-129, Petition for a Nonimmigrant Worker.