Haven't checked this thread in a long time, didn't realise there are some of you still waiting for a response.
Your files probably got caught in the final review just when the coronavirus hit, and so they've been on hold for a while as offices have closed and workloads have frozen.
I know it's a bit nerve-wracking but as long as everything is in order, you application should be fine.
It's true, now is not a great time to land, and even if you got your documents, you would not benefit from the exemptions and so would not be able to land as your COPR would be dated after March 18.
Treat it as a blessing in disguise, you'll be given more time to land after this thing blows over and you can come at a much better time.
Check your accounts for GUs every day, that's really the only sure sign that there's movement on your file. Although not everyone sees GUs on their applications before they get PPR, many do.