EE Application in processing since Jan2020

[De@dpool]

I have been trying to find some answers regarding my situation and unusually long wait. I hope no one is in my situation and waiting for this long, but if there is someone I would appreciate your PoV and inputs.

My wife(primary) and I applied for EE in Jan20. In Dec20 we were asked for PCC (Police verification) again. Not sure why. Our application status had reached 100% around 6 months time and now it no more shows any % but says few things are being reviewed or/and pending viz:

1. Review of Eligibility
2. Background Check
3. Final Decision

In the meantime (these are in recent months), my Indian passport had to be renewed. And my H1B now will be changed to H4 (waiting for approval). I updated webForm with these changes a month ago. I can understand IRCC needs time to process these changes but even before that my application has been in processing for over a year.

Few questions/concerns

1. Why is it taking so long and is it common?
2. If I have not changed the country of residence why was I asked for PCC again?
3. Since its been over 18 months, would GCMS still be helpful?
4. Has anyone come across anyone in similar situation? If so, please share the thread so I can reach out to that person or if you have any details about how it went for that person would be great.
5. Most importantly, what can I do now while I wait for PPR?

Your time and knowledge would be much appreciated.