Thank you for the credentials, that is happening because your Containers has no equal height. It's the middle container has the tallest height and the left and right container's height can only get as much as the border.
To resolve that, apply the border (left and right border) on the middle container instead, since that is the tallest container its border should cover the other container.
Another way to resolve that is to set the Bar's Flexbox Vertical layout to Stretch
That will make all the Containers of that Bar to have equal height regardless of the content inside those containers. If you do that, set all your Containers' Flexbox Vertical to Start, so the content will start at the top and won't look dis-align.
A Complete Guide to Flexbox
Regarding the phone number and email font size, please use the
rem unit on the font-size option.
rem unit will be based on the Theme Options > Typography > Root Font Size and the way your Root Font Size was set up,
rem should be responsive properly.
Hope it helps,