Defrosting issue?

Hello, and thanks for having me here.
I hope I read the instructions right and am posting in the right place?

I have a Trane model #TCONT824ASS52DA and I have a defrost question.
The unit is 7 years old and never gave me trouble once, but in this extreme cold weather I am noticing something I never noticed before.
It is 19 degrees right now and I know a bit about defrost mode, but after googling about my issue I have 3 different responses so I decided to join here and get and expert opinion.
OK,
When my unit goes into defrost mode, the fan keeps running and begins to blow cold air dropping the house temp 2 degrees before the heat comes back on.
Is This normal?
I have read it is normal to do this, I also read the fan is supposed to stop running until defrost is complete, and I also read that the unit will continue to blow warm air by switching to emergency heat?????

So, what's the verdict? Is my unit functioning correctly or is there a bad converter or something else.
I have the unit calibrated perfectly

Thank you

MrJoeCal

source https://hvac-talk.com/vbb/threads/2236524-Defrosting-issue?goto=newpost