Pocket was working fine on my Kobo Elipsa till last week, but there seems to be a new sync issue since Saturday: "Something went wrong" and no new articles arriving. At least one Clara BW user has the same issue, as described in this Lemmy thread:
https://sh.itjust.works/post/19063423
Unfortunately, I tried signing out of Pocket to fix this, which didn't help but means I lost access even to the articles that had already been synced earlier
Also a PSA: I had my Kobo on sideload mode, but signing into Pocket kept failing with an "Unauthorised" error on Kobo's end. Signing into my Kobo account fixed that problem (I was able to sign in to Pocket, although articles still failed to sync once I was in). So if you're in sideload mode and signed in to Pocket, you might want to stay that way and avoid getting yourself signed out!