Photoshop CEP - How to preserve kerning after changing text content?

I tried different approaches to preserve "set kerning between two characters" options. For some reason after I change text inside textItem and try to preserve styles - it changes from "Optical" to "Metrics". How do I overcome this behaviour? Nowhere in code I set kerning option to metrics and I expect it to be saved. It is not in 100% of cases. I attached file with reproduction. For first string in file - everything works as expected - for second kerning changes.