If "A" or "AB" is registered first, the following message will be displayed when trying to register the other.
Some symbols have already been used as 'Replace what' values.
This occurs to prevent the same character or character string from being replaced multiple times by the product design.
As a workaround, use the Autocorrection script instead of Character Replacement or Text Replacement.
In the script, if the field value contains "AB", convert it to a blank character first, and then search for the remaining "A" and convert it to a blank character.
The IValue object and the properties under it can be used in the AutoCorrect option.
For character string replacement, the general character string replacement method can be used.