Twitter has multiple feedback channels, mainly one for general customer [1] (called "one" below) , some for developers [2][3] (called "second" below), and some for ads (not relevant here).
[1] https://help.twitter.com/en/forms
[2] https://twittercommunity.com/
[3] https://developer.twitter.com/en/support
The problem is that, the first one basically only deals with content/account related issues ("my account is locked" etc.), while the second one strictly only deals with API issues.
If you encountered any technical issues on Twitter's end when using it, even if you have a proper STR and everything, there is just no way to feedback it.
I have tried both; the representative in one is often beyond clueless about what I said. In second channel, they will close your ticket/question as soon as it's not related to API. I found myself frustrated about this situation often, knowing something they can improve/fix fairly quickly (at least, straightforward) once elevated, but there is no way to reach the right person.
Without a sales contact, paid support agreement, friendly insider, or some other relationship through which to make a submission, I simply wouldn’t bother. I’d suggest spending your time instead helping those who would be grateful for it.