On your master page have you brought up the guide called "bottom of browser" and rested it against the bottom of your bottom bar? Also sometimes locking down that bar, or grouping things in it seems to help, but make sure you keep enough undos ready beacaue it might make it go wacky.
So basically the bottom of page and bottom of browser guides should kinda almost overlap.
I tried locking the footer fill rectangle and that didn't work. All is correct on my side. Might be a Safari issue (Firefox looks fine).
Can anyone check this using another browser, and better yet anyone on a Windows machine who can peek at the bottom of the browser? Should be blue not cream. Thank you!!
If you hit CTRL/CMD +A, you will see text in the bottom area under the blue that says
"The Creek animation, podcasts & recording adventures
were made possible by the funding and participation of the following creek friends."
I am guessing that this paragraph is causing the issue, though I can't say I have any ideas as to why it is. Try deleting this text and publishing. If that works, try re-introducing the text from scratch. you might also be able to group this text with the other elements in the blue area using CTRL/CMD +G