Hello,
First thanks for screenshot and video.
Regarding the logo:
This is what we see on init of contact section:

If you mean when scroll down a bit, like below:

This is the expected behavior, since the demo was not designed to change logo/header layout on this situation.
Regarding the right white bar, this is a browser bug when resize the same page too much times (normally while testing). Just closing the current tab and opening the website again in a new tab should resolve the issue. Note that this will never occurs in a real mobile device, since the website will always open at same resolution.
Regarding “NoHD” scrolling issues, please always reload the page again when changing from mobile resolution to a desktop res. This demo runs javascript code on first load of page to make the scrolling functionality (the code check if is mobile or desktop and do somethings based on it). This mean that only resizing the page will generate that issues.
Still on the video, in the blue section you show a small scrolling. This is because your section height overtakes the browser height. The solution on this case is reduce the section height by changing font size, reducing the spacement between texts (margin and paddings). Reducing the content height in 50 ~ 100px should resolve this issue.
We hope this helps!
Please try that and let us know if you need further assistance.
Kind Regards,
Rodrigo.