Currently, to determine whether to show local development version of a card, it makes a request to http://localhost:8080 anytime you view the card (even in production). This means, if the user has something running on port 8080, or network configuration cause that port to timeout rather than refuse connection, the card will hang completely, with nothing being logged at all in monitoring.
Relying on port 8080 for the dev server is VERY problematic and extremely bad practice. This should change. We’ve wasted several hours debugging our app over the months because of this silly issue that keeps reappearing at random, making debugging ui extensions cards very annoying.
I have no idea how this flew under the radar but the dev team should be made aware of this.
Port 8080 is the most common port so the chance anything is running on a user’s system on that port is VERY LIKELY, which means cards will NOT work for that user!
Either use a different, uncommon port, and have a timeout so it doesn’t hang forever and still shows the actual card, or use a different mechanism that isn’t affected so heavily by network configuration and running software.
On a similar note, port 5173 (and 5174 when default in use) is also the default port used by Vite, which adds another risk of clashing with running software (but less problematic because it seems to discover the actual port by hitting the port 8080 already mentioned).