wp_set_object_terms not working correctly

[yfain]

Hello,

we ware developing a tool to import data from xml files.

We used wp_set_object_terms for creating terms but with WordPress 5.1 it is not working correctly.

I can not explain what the problem is. Under wordpress 5.0.3 it workls correctly.

I've added an image, where you can see the problem. The first record was created with WordPress 5.1 the second with WordPress 5.0.3