In the meantime, this worked for me:
Set your custom menu link to an anchor and place that anchor somewhere on your page — I put mine at the top. So now my menu text is “shows” and it links to “#shows”
Next go to your boxzilla box and select Load this box if “everywhere”
Autoshow box “yes, when at element” and type in #YOUR_ANCHOR
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Then make sure you purge all of your caches (theme cache and browser cache) to see if it is working properly.
Wishing you success!