[Membership 2 Pro] Incorrect expiry date

We have created a membership plan for 6 months. Member registered today, i.e. 4th December 2018.
Membership 2 is showing the expiry date as 2nd June 2019, whereas Stripe recurring payment shows the next payment date as 4th June 2019.
The actual expiry date should be 4th June 2019. I think the issue is, it counts 30 days * 6 = 180 days, whereas, some months are of 31 days. Please advice.