This happened back when WoW retail 10.0.2 was released and Sexymap was updated for it. After the update, the Z-Perl addon button (https://www.curseforge.com/wow/addons/zperl) no longer appeared on the map and doesn't appear in the Buttons tab either. I waited a bit before posting this cause Z-Perl took awhile to update (Updated the day of posting this) and I wanted to see if the latest version may fix it but it didn't. If I disable Sexymap, the Z-Perl button reappears on my minimap.

I'm using the latest version of Sexymap 10.0.7 and the latest version of Z-Perl 7.0.3 as of typing this.

This isn't my responsibility to fix.