To make it easy I have created a quick repro solution for you guys see attached.
Bring up the Refactor menu on the ClassA and select Move Type to File
The Imported Namespaces will be missing a space and also be gapped out.
The Namespaces don't matter I just used some random ones to try and reproduce the issue.
This was also in 16.1.6 and 16.1.7 but I didn't have a repro.