[ownedbycats]

I did some more testing.

First I thought that Reading List simultaneously changing the series column and the #kobocoll column might've been breaking things. I checked them seperately.

I found I could only replicate the bug reliably when removing from a reading list that had the series-like column set. (I didn't notice this before, but this bug never occurred with my "Send to Device" list. No series column on that.)

To isolate it to the series column and not the composite, I switched my #onreadinglist composite column to instead check for the presence of "To Be Read" in the #kobocoll column. No effect.

But what did help was removing the series column entirely from the View Manager sort order.

Unfortunately this now means that my books are not actually in order anymore; I'm considering dumping the series column entirely. But I'll try creating a new column with a new lookup key; I'm wondering if the old column might've gotten messed up in some manner.