Why are envelope requests not sent on route changes in Firefox (Angular + Sentry)?

[awoc]

I'm using Sentry with an Angular application (Angular 19.2.14, Sentry SDK 8.55.0), and I’ve noticed that envelope request during route changes are not sent in Firefox.

In Chrome and Safari I can see envelope requests in the network tab when navigating routes or when unhandled exceptions occur. However, in Firefox this behavior breaks down. Is this a Firefox specific issue?

[mydea]

hey, you simply do not see this in firefox dev tools. They should actually still be sent. We noticed this ourselves here: microsoft/playwright#34497. Apparently, Firefox implemented support for keepalive in v133. But it seems that those requests (and we use this for sending envelopes) for whatever reason do not show up in dev tools. They should show up in sentry though - if this is not the case, please open an issue, because then there would be an actual bug! 😅