Incorrect judging of browser versions

[Winqov]

Is your suggestion related to a problem? Please describe in detail.

No, it's not. I'm using the last version of Firefox ESR, currently 102.15.0, which is the default on Debian, and it works perfectly fine. I had to block the pop up, so it doesn't show up on each visit. Not a great user experience, to be honest.

Describe your suggestion
Checking and telling the user to update their browser should be beyond your scope.

I suggest you ditch this anti-feature completely, as on windows, all relevant browsers auto-update themselves, on phones, the shops auto-update them too, and any linux user will keep their system up to date.

Describe alternatives you've considered
As an alternative, you could fix the issue by just keeping this "feature" for very outdated browsers that would really have trouble rendering your page.

Additional context
My guess is that you're using the user agent for the check. That would explain why ESR is identified as outdated.

Firefox ESR 102.15.0 user agent:
Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0

LibreWolf 117.0-1 user agent:
Mozilla/5.0 (Windows NT 10.0; rv:109.0) Gecko/20100101 Firefox/117.0
(LibreWolf is basically upstream Firefox hardened by default.)

As you can see, ESR looks like an outdated version of Firefox, while in reality, 102.15.0 was released on 2023-08-29.