For freezes issue
I checked
by clicking on achievement tab it did not freeze.
But On finish course it seems like it freezes. I will have to check it on backend code. kindly share ftp credentials too in private reply.
Refer :
https://screencast-o-matic.com/watch/cqhI28ZREO
even if I have set the course duration to 9999 days, on the course page it says '27 years' and not 'Unlimited Access'
This issue has been fixed, please update plugins to latest version.