Hi there,
Thanks for reaching out to Adobe Community.
Partial or limited data is much more common, and is expected depending on your implementation. Because of the wide range of differences in browser types, recording every link click is not guaranteed. If you see an abnormally lower number of clicks than expected, you might want to take a couple of things into consideration. The list of these items can be found in the doc below. Please visit the link to understand the nitty-gritty of visitor click map:
https://helpx.adobe.com/analytics/kb/no-data-clickmap-overlay.html
Thanks!