I am using Firefox ESR 78.7
Settings are not saved
Always fixed at GMT 0

Caused date pickers to break in really weird ways. Possibly related to having set privacy.resistFingerprinting=true.

I do not understand the option "automatically update timezone based on my ip address"
Isnt the whole reason of this addon is to NOT give out real timezone/location? so if im connected directly it will not spoof? but when im connected through a proxy it will update timezone based on the proxy?
You should explain more clearly in the extension description about how it works and the options it provides...

Works as advertised, but lacks option to selectively disable or use specific timezones on certain sites.
Many sites will not work with this enabled including those "protected" by googles already broken recaptcha. On these sites you end up in an endless loop of recaptcha prompts and are unable to login and/or access content.
Add an option to disable or select a timezone on certain sites and it would be a whole lot more useful.
There isnt even an option to disable it from within FF, other than disabling the whole extention in FF options.

I click on sync time zone w IP address and then click save. It doesn't save/ doesn't work.