Is it just me or is KOReader Sync broken now? I'm using the beta.

[GanWeaving]

KOReader Sync between my X4 and Koreader on Kindle and Readest on iOS worked but it stopped. From the kosync logs:

Your X4's User-Agent flipped from ESP32 HTTP Client/1.0 to FreeInk-ESP32 on 2026-08-26 — you reflashed it to FreeInk firmware that day.
Every X4 record that cross-synced with a Kindle (synced_from KindlePaperWhite4, native_device CrossInk X4) is dated before that — 30 Jul, 17 Aug.
Every book the X4 has touched since the reflash sits on its own private hash. Volume III → e6a1f2bf, while Kindle + Readest → 8c5abac1.

Books that were already on the X4 before 26 Aug still sync, because the file on the device never changed. It's specifically books newly downloaded by the FreeInk firmware that break — its OPDS download produces different bytes (or a different hash) than a plain HTTP GET, which is what KOReader and Readest do.

So this is a FreeInk firmware regression, not a server problem. Options:

Quick test / workaround: copy the OPDS .epub onto the X4 over USB instead of using its downloader, then check the fingerprint. If it reads 8c5abac1, the downloader is the bug and USB side-loading is your fix going forward.
X4 as source of truth: pull the X4's epub off via USB, load that exact file into Readest + KOReader (drag in, not OPDS). All three then share e6a1f2bf.
Report it to the FreeInk project — the timeline is unambiguous.

Anyone else noticed this?