I am not sure why this was down-voted. Anyways, if someone stumbles upon here with a similar kind of problem, I would request you guys to check the conditions (specially if there are any custom ones) that are applied to the block when it is placed inside a region.

For me it was such a case and happening because of some default values getting stored from one of my custom conditions plugin.

Hope this helps somebody.

I had to check the conditions applied to the block when it is placed inside a region.
For me, this was the case. The issue happened because of some default values stored from one of my custom condition plugins.