Scripting system.tag.copy() collision policy problem

I have a problem with the system.tag.copy() script. The function works but when I copy a modified UDT it creates another instance/UDT with the suffix 1, 2, 3 etc. colisionPolicy doesn't seem to work and even the default one which should reject copying a UDT with the same name doesn't work and more are still created. What could the problem be?

udtDef = '[AB]_types_/UDT_PowerLimitHistory'
udtInstances = '[AB]PowerLimitHistory'
tags = [udtDef, udtInstances]

destination = '[default]'

policy = 'o'

system.tag.copy(tags, destination, policy)

image

Regards
Michał Góralczyk

Does anyone know what could be the cause?