On my browsers [Microsoft Edge 114.0.1823.58; Chrome 114.0.5735.134] when I have 7tv enabled I cannot "tag" (i.e., use @ to auto-fill) a twitch user that was not talking before I opened the page of the stream I'm watching.
I was able to "tag" people who talked in Twitch chat after I opened the page a few days ago, so I'm not sure if there is a setting that may be interfering. I use BetterTTV (7.5.4) and FrankerFaceZ (1.57) with 7TV (3.0.9) extensions on Microsoft Edge.
Apologies if this isn't the right place or tag and let me know what to change it to to get the right help!