H1B transfer, Backdated approvals & the Non-Immigrant status during H1-H4 COS due to backdated approval?

Here is my unique scenario, I request your expert opinions please! Thank you.

This is from the past, but I just want to be clear on what I have understood so I can be rest assured this does not interfere in anything in future.

I was in H1B with employer A, say as of July 2018.
In Aug 2018, I join employer B on H1B transfer receipt.
The approval for this H1B does not come until Dec 2018.

But when it came, it came with Validity From and To as Aug 2018 – Sep 2018.

My Spouse is also on H1B so in Dec 2018, as soon as we got the Backdated H1B approval, my i-539 COS to H4 was filed almost within 3 weeks on receipt of backdated approval., by Jan 2019 and I stopped working as soon as the notice was received.

And the story continues – my i-539 COS to H4 approval happened only on May 2019. 4 months after it was filed.

Did I accrue any out of status here ? or was I in the so called Period Of Authorized Stay since I filed the COS quick ? To me, there isn’t any out of status as I understand the process.

Please advise. Thank you.

Please ask any questions if my case is not clear or if I did not make it clear.

Note: After all this, a year ago, I got a full 3 year H1B extension with the same employer(this itself would mean I did not accrue any wrongful stay, correct ? )

I replied to your question that you posted on another forum.