Confused over intermittent USCIS case status

Our petition I129 got denied, We have filed MTR with enough evidence, After 3 months of wait On the same day our case updated to 3 statuses like below.

A) Case Reopened, Denied petition reopened, to reconsider their denial decision

B) Petition Approved (I797A Backdated approval)

C) Case reopened (After approval update), We sent you a notice and follow steps.

1)We have received Approval notice and Reopen notice.
2)In Reopen notice USCIS never mentioned they are reviewing approval decision, Just mentioned they reviewing my case as a motion to reopen or motion to Reconsider. (NOTE: Both Approved and Reopen notice has same notice date) .

Employer/Attorney reached USCIS, even Tier-2 officer unable to answer the exact situation of my case or H1B approval notice or valid or not. Even they are not sure my case reopened or not. What should i do in this case? My Legal team suggested to file an extension with npt(Nunc pro Tunc), Is it best way to get resolved?

Once USCIS approved a petition I129, Petition for non-immigrant. If USCIS canceled or Reopened the approved case do they notify to petitioner by sending notice? Else they can simply cancel/Reopen the approval decision without sending any update

Your legal team suggestion is correct. If you are unsure, it is better to file the same. You can explain the situation of your entire case and submit proofs and share details.
Yes, they usually do it. Only way to know is calling them or your attorney following up…
The online system can be very confusing as it gives weird statuses as well.