Attribute Assistant - Incorrect Increment Value

I’m using Attribute Assistant to generate an ID using the GENERATE_ID method.

Instead of incrementing by 1, the value increments by 2 every time.

The log file shows a curious thing:

Field Name: STRUCT_ID was found at index: 2
            Trying: GENERATE_ID
            14 is the existing value and the interval is 1: 5:11:23 PM
            SEQCOUNTER changed to 15: 5:11:23 PM
            SEQCOUNTER changed to 16
            STRUCT_ID set to SWMC_00016
            Finished: GENERATE_ID

Thus it appears that AA recognizes the proper start value, realizes it needs to increment by 1, but then proceeds to increment by 2!

Here are the relevant entries and fields in the two AA tables. There is only one GENERATE_ID rule for this TABLENAME, so that can’t be an issue.

Any ideas what is happening?