Bug when using target fields in picker as item list column? DONE

Hi,

we recently upgraded our DEV-Environment to latest 2021.1.2.136.

Today i was evaluating the new version with our existing processes, and stumbled upon something that didn't occur to me in the past.

I have a crucial picker field in an item list, that has target fields from some of the columns in that same item list.

It works in our current PROD version (2020.1.3.411).

In 2021 it throws:

"Sequence contains no matching element" - Error, and the value is not transferred into the target field.

I tried with a different field in another process and another itemlist, with different datasource - same result.
If I remove the target fields from the picker, it works. Changing to autocomplete works, but it is inconvenient for that purpose - picker is better as autocomplete, especially with the bigger size in 2021.

It works with picker fields outside of item-lists. Is there something I missed, or is this a bug? It's a showstopper for 2021 for us.

Can someone confirm this?

Thanks!