KOReader on Kobo + KOReader docker

[nuovodna]

Hi everyone,
I am using Koreader on Kobo Clara BW plus Koreader in a docker (https://github.com/zephyros-dav/docker-koreader) running on My Raspberry Pi 5 accessible from the Internet.
My goal is to read from the Kobo and from other browsers (from work or on iPhone) by synchronizing the progress of reading and the highlights.

I currently use a shared folder with Syncthing that runs on both Kobo and server. But when I open the book on Kobo I don't see the highlights but only the current position of the book (and viceversa when reading in the browser).

Seeing the Metadata.epub.lua file it seems to have the highlights from both sources but opening the book from the single koreader (kobo or browser) i can only see the highlights made on that koreader instance.
Am I doing something wrong?

Thanks in advance,
Emanuele