I tested this on our 3.9.1 server and could not replicate the problem.
I think I followed Britta's steps:
From a record bucket I selected two records
I chose Actions-->Merge Selected Records
I selected Toggle Holdings Display and Edit Call Numbers and Items
The result is shown in my attachment
I tested this on our 3.9.1 server and could not replicate the problem.
I think I followed Britta's steps:
From a record bucket I selected two records
I chose Actions-->Merge Selected Records
I selected Toggle Holdings Display and Edit Call Numbers and Items
The result is shown in my attachment