1. the gap between the header and menu has appeared again

On Frontier Options -> Display check the value of Header Height. It’s showing as 150px now when it should have been 140px. You may have changed that a while ago.

2. on the visitor map page the pins are not in the right place BUT if you open it up on a different window it is fine.

Does this happen with other themes? I’m guessing it does since the plugin you’re using doesn’t add it’s own css. Add these on the Custom CSS option.

.wo_map {width: auto !important;}
.wo_map, .wo_map * {
    font-size: 0;
    line-height: 0;
    padding: 0 !important;
}

3. just went into one of my galleries and one of the albums was not showing correctly.

Which one specifically? They look fine on my end. You seem to be using a plugin and not the default WordPress gallery.