If I'm not a complete dumbass who unable to find this "pill", there is a bug on TB (115.3.1) with Conversion addon (v5.3.1) and DKIM verifier (v4.1.3), that cause this pill to disappear.

Help me find this pill (if it exists):

And here is the same email opened in the default viewer:

The only thing that could be relevant that I found in TB's error log:

Uncaught TypeError: MutationObserver.observe: Argument 1 is not an object.
    <anonymous> chrome://conversations/content/stubWrapper.js:21
6 stubWrapper.js:21:13
    <anonymous> chrome://conversations/content/stubWrapper.js:21

Thanks.