Unstable posting position and incorrect voting activity on iPhone

Expected behavior

• Voting: only available for logged-in user. If not, requesting log-in.
• Smooth scrolling on the posting

Actual behavior

• Voting: sometimes, it is possible to select like button without log-in
• Scroll up/down makes unstable position for a posting

How to reproduce

1. Access to busy.org using Safari/Chrome on iPhone
2. Select a specific posting and scroll up/down
3. Click like button

• Browser: Safari, Chrome 62.0.3202.70
• Operating system: iOS 11.0, iPhone5S

Recording Of The Bug