@Mastodon @Gargron I don't know if I've already reported this issue, but https://bridge.joinmastodon.org doesn't handle correctly users with a "base domain" different from the mastodon's domain.
For example, my username is "@zoddo@zoddo.fr", but my Mastodon's instance is on "mstdn.zoddo.fr". When I enter my username, the website crashes, and I should use "@zoddo@mstdn.zoddo.fr" to access it.
But doesn't this will associate a wrong username with my twitter account?