Checking for a specific chapter translation of a long-running series always feels like waiting for a delivery truck you're not sure is even on the route. For chapter 455 of '19 Days', I haven't seen it pop up on the official platforms I usually track, like the Bilibili Comics app or Webcomics. Those are the main legal hubs for the English version. Sometimes there's a weird lag of a week or two between the original post and the official translation going live, and other times fan groups just blaze ahead and put out their own versions on aggregate sites way faster, which can make the official one harder to spot. The official schedule isn't always super transparent, which is frustrating.
I mostly stick to the Bilibili app because I want to support Old Xian, but I'll admit I've caved and peeked at fan-scanlated chapters when the wait felt eternal. The quality can be really hit or miss though—some groups are careful, others just run the text through a translator and call it a day, and you lose all the nuance of Jian Yi and He Tian's bickering. For 455 specifically, my usual scanlation bookmarks are still showing the previous chapter as the latest, so my guess is we're in that awkward in-between period where the raw is out in China but the translation team hasn't released their work yet. I'd give it another few days before checking the app again, that's usually when things quietly update.