I use ElvUI and Pet Tracker doesn't seem to like working with the Main Map in showing where specific pets are in a zone. I have to disable my UI, search for the pet, then enable it in order to find the spots of a pet like the Crimsonwing Moth in talador. I've attached a photo of what my map looks like with the UI on so you can get a better understanding

Here is one with my UI off:

I'm having the same issue.

Update: Try disabling the World Map skin in the ElvUI settings.
-- I was able to get it to work by disabling the ElvUI addon, reloading with Pet Tracker enabled. Toggle the settings on the World Map. I enabled battles. Then enable ElvUI and it should be showing on the World Map.
-- Next thought was to disable the ElvUI skin, which may help, but I haven't done much testing on it.

After looking through the ElvUI forums I came across some posts where people where having mini-map issues, which might also apply to the main map. Look at this post https://www.tukui.org/forum/viewtopic.php?f=5&t=2317 and find #12 on the second page. (The entry number is located in the top right of each post). Perhaps that build will resolve the matter for you?

Can confirm, with ElvUI disabled, everything is working. With ElvUI enabled, I cannot click on the magnifying class (but icons stay active if enabled without ElvUI enabled).

Can confirm, fixes the dropdown for the Mini- and Worldmap!
EDIT: the latest elvui dev

Sorry, but this is nothing I can help with.