Are you talking Tabs or Tiles ?

• https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

Tabs So after the URL is set for homepage put a Vertical Line ( | ) at the end followed by another URL = 2 Tabs open and repeat for more tabs to open at start. Or When have all your tabs open that you want to have click on the Last Tab and Bookmark All Tabs and they then will all be bookmarked in a Folder together. Or when you close down Firefox go into Options at the very top put a Check Mark Restore Previous Session Or

• https://addons.mozilla.org/firefox/search/?platform=windows&q=session%20manager

Tiles

• https://support.mozilla.org/en-US/kb/customize-new-tab-page

Please let us know if this solved your issue or if need further assistance.

If going to Customize always backup :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

You need to make sure that you pin pages (see the three-dot menu on each tab) to each tile on the Firefox Home page to make sure they can't be replaced.

If you do not keep pinned tabs then check for issues with the preferences.

• https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save