[theducks]

I think I am doing something wrong (K4NT)
I create collections based upon {Series } << This works

but some books also belong to another series : {#split_series}

It is my intent that a few books will belong to 2 collections. Note: the same series name per book could be in either column (but not the same in both for the same book... BUT some series are hierarchical, so the root could be in one and the root.subseries in the other)
If I also define this, then many books don't appear in a collection on the K4.

OK I looked at the Log Some series do not get created, yet were on the device. (at least 1 had only series. not in either section saved nor deleted)
Others WERE in a series (collection. from the single column run) and the collection was deleted.
Could this be an bad interaction between the 2 columns

Spoiler:

=== Settings:

Column: Series
Action: Create
Prefix: ""
Suffix: ""
Minimum: 1
Ignore: ""
Include: ""
Rename from: ""
Rename to: ""
Split on: ""

Column: Split_series
Action: Create
Prefix: ""
Suffix: ""
Minimum: 1
Ignore: ""
Include: ""
Rename from: ""
Rename to: ""
Split on: ""

Never delete/modify these Kindle collections:
Action when toolbar icon is clicked: Create Collections
Preserve existing Kindle-only collections: True
Ignore prefix/suffix when comparing Calibre names: False
Ignore case when pattern matching: True
Reset collection times: False
Ignore exported collections db: False
Only build a diff database: False
Kindle Model: 400
Calibre Personal doc tag: [PDOC]
Kindle collections file: I:\system\collections.json
Plugin customization file: C:\Users\<me>\AppData\Roaming\calibre\plugins\Kind le Collections.json
System Encoding: mbcs