Thanks, Tom.  Apologies for the extremely late reply.  

I don't use the online reader.  My primary reader of choice is Chunky on iPad.  I'm looking for the functionality whereby I start reading a comic (comic book 1) and then midway through, I open another comic (comic book 2).  Once I'm done with comic book 2, I want to re-open comic book 1, but I want it to open where I left off.

My setup is:

- Synology DS3617xs

- Ubooquity via the Linuxserver docker container

- Chunky comic reader on iPad

Correct.  Ubooquity doesn't remember:

1. which comic(s) I've read
2. at what point I've stopped reading in a comic

By contrast, Comicstreamer does remember, by default.