the visual and audio notifications of incoming emails to the inbox do not function correctly on gmail on Linux OS

The visual and audio notifications for incoming emails being posted to the inbox of gmail under Mozillia Firefox do not function correctly when ran on a Linux Mint operating system computer. I can get the visual notifications to work as long as the Firefox is open but once that session is closed the visual notifications are no longer issued, i.e. the setting to issue those notifications are not being saved upon closing of the browser. I can get the audio notifications to work on a sporadic basis. I go into the settings on gmail and choose one of the audio sound notification choices and it works a few times when income emails are received into the inbox, but then just stops even if the current firefox/gmail session is still open. My theory is that those firefox/gmail settings are not getting preserved/saved in proper manner to be available for subsequent sessions of firefox/gmail because firefox/gmail does not understand the FILE STRUCTURES of Linux Mint Mate so that those settings can be properly preserved for use by subsequent sessions of firefox/gmail. Please consider fixing this. Thanks.