Is it a Mozilla page? I'm not familiar with that survey.
Three potential issues to check:
(1) Did your home page get updated to that address. You can check the Custom URLs setting on the Settings page. See: https://support.mozilla.org/kb/how-to-set-the-home-page
(2) Is Firefox stuck restoring an old session over and over?
(3) Is it possible one of your add-ons launches that page at startup for some reason?
(4) Is it possible the shortcut you use the start Firefox was hacked with that URL for some reason?
For #2-#4, I suggest posting this problem on the Mozilla Support site for further investigation. They have a team of support volunteers to troubleshoot malfunctions with your currently installed version of Firefox, while this site is focused on idea submissions for future versions of Firefox (looking ahead anywhere from 8 weeks to many months). Here's a link to the new question form (for Windows/Mac/Linux): https://mzl.la/3y1vQUQ
