This is an issue, I summarized here: Windows10 V1903: Update KB4517211 causes printer issues.
I will escalate this thread to Microsoft moderators and ask to forward it to MS developers.
Addendum (Sept. 30, 2019): It worked, Microsoft confirmed the bug - see Windows 10 V1903 status page - but I don't agree with Microsoft's explanation to blame KB4522016 - see also my blog post Windows: Printer issues after Sept. 2019 Update confirmed