Heatmap captures blank screenshot or no screenshot

Hi
we purchased the heatmap plugin to track activity in our webapp and while we are getting data, we are getting either a blank screenshot or the following notice

There have been 63 samples recorded so far. However, no screenshot has been taken yet. If there is a “Screenshot URL” for this heatmap, it may take a while for the screenshot to become available as a user first needs to open this screenshot URL. Depending on the sample rate this may take a while.

even though there is no screenshot url. Tried the tip at https://matomo.org/faq/heatmap-session-recording/faq_25413/ but could not get that to fix the issue. We are currently using 3.14.1 in our production environment as we have not finished testing 4. Anything else I should try?

Thank you

Hi there,

When you visit the page you are trying to track, do you see any errors when sending data to Matomo?

Thanks,