Q: Can you explain the multiple status updates in the system after submitting a reformatted manuscript?

These status updates seem to be for The BMJ. Also, I assume the updates occurred in the sequence you have mentioned them. If so, here is what they seem to mean.

• Awaiting Reviewer Selection: After the manuscript was reformatted as per their guidelines, the journal editor decided to send it for a peer review, and accordingly, began the process of inviting peer reviewers.
• Awaiting Third Opinion: The manuscript may have been reviewed by at least two peer reviewers, who had conflicting views on the quality of the research, manuscript, or both. Therefore, the journal editor decided to send it to a third peer reviewer to resolve the conflict.
• Awaiting Screener Assignment: This typically means that the editor has not been able to find the requisite number of reviewers and is still looking. If the status changes occurred in the sequence you have mentioned, this might be challenging to interpret. In this scenario, it could mean that the editor has not been able to find a third reviewer.
• Awaiting Second Opinion: Again, if these updates occurred in the sequence you have mentioned, this is not easy to interpret. In this scenario, one possibility could be that the editor has decided to refer the matter to another internal editor.

As it has been three months since you submitted the changes, that too, only for formatting, and as the manuscript has gone through several status changes since then, it might be a good idea now to drop a mail to the editor with an aim to understand the current decision on the manuscript. If they do not provide a satisfactory response or are likely to take longer with their decision, you may consider withdrawing the manuscript and submitting to another journal. All the best for the next steps!

Related resources:

• Tracking your manuscript status in journal submission systems
• How do I write an inquiry to the editor about my manuscript's current status?
• Keep calm and wait: A guide to understanding journal statuses [Handbook]