Dilip, did you test on the current version of Gutenberg? Like the one from 3 days ago? or the one from 4 days ago?

Your plugin has not changed in over a week. Also you marked it resolved without checking with me or responding to the problem. Thats a tad upsetting.

Again your plugin does not render out the answer in the last 2 updates of Gutenberg.

Question but no answer in the admin:
https://www.dropbox.com/s/gqvx2moh3a38cc7/Screenshot%202018-06-08%2016.04.58.png?dl=0

Block in code view pre answer:
https://www.dropbox.com/s/2w7335c71hylyhq/Screenshot%202018-06-08%2016.05.11.png?dl=0

Block in code view in the admin after i added the answer via the code editor:
https://www.dropbox.com/s/9uir70jo2iqrvo2/Screenshot%202018-06-08%2016.06.04.png?dl=0

Block with answer added:
https://www.dropbox.com/s/udzlm9inoimlgbs/Screenshot%202018-06-08%2016.06.20.png?dl=0

If I add the answer manually, it will render in the frontend.
This means its an admin issues.

These are the errors I get when I add your block to Gutenberg, and yes i check with no other block on a new page.
https://www.dropbox.com/s/aj504npfv74tz67/Screenshot%202018-06-08%2016.18.58.png?dl=0