Firefox should normally remember the page zoom as part of the Site Preferences.

Are you possibly using Private Browsing mode ?

• https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history
• https://support.mozilla.org/en-US/kb/common-myths-about-private-browsing

Note that Firefox has a Zoom section in Options/Preferences to set the default zoom level for webpages.

• Options/Preferences -> General -> Language and Appearance -> Zoom

I have no idea what has happened to Firefox??? It is slow and freezes between pages. At first I thought it was my internet connection until I opened Microsoft Edge and the internet is working at its usual speed. The zoom feature is still not working correctly... I am not in Private Browsing. I have tried to set the zoom in the options menu and it will not stick. It resets to 100% over and over. I have tried to change this setting 10 times with no success.

This all started the last time I restarted Firefox after the last update. Since then the browser has been slow, locking up with constant messages saying the browser is frozen, before you can react it decides to react it finally starts loading the page? I have restarted the computer, restarted the browser multiple times. If my computer goes to sleep... the browser locks up the entire computer.

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

I sort of cheated to fix this problem... I used Microsoft Edge to import all of my information and then uninstalled Firefox and removed all of the files. I then reinstalled Firefox and allowed it to import everything back from the Edge browser. That has seemed to correct the problem.