Thanks for playing!
The two hands you posted on multihand blackjack are not a bug. Let me explain. Here is the flow for dealer peek and insurance:
1) You are offered insurance whenever the dealer shows an Ace.
2) And then after that you can choose insurance.
3) And then only dealer peek happens.
For your 2nd posted screenshot, insurance wasn't offered because dealer wasn't showing Ace. The shown card was a 10. In that case, dealer peek plays but not insurance.
Hope that clears up the situation for you. Happy to walk you through further if you need more clarification.