I too agree, I bought a lifetime license and now I am being annoyed to pay once more.
I have been using Enpass for years and really enjoy using it and this really makes me like it less.
I eventually did buy the lifetime again for premium however if this happens again, I'm switching again to something else even though I really do not want to.
This is just disrespecting the customers in my opinion.
At least there should have been a decent discount for pro users upgrading to premium.