Microsoft has yet not been able to provide a bug-free Windows 10 1903 update to the users. Even the latest update KB4517389, while claimed to be bug-free by Microsoft at the time of release is not really without issues it seems.
Many users reported the update breaking Start Menu. Microsoft subsequently acknowledged it with a promise of resolution in late October in the official forum.
Microsoft has also acknowledged that the update KB4517389 is breaking Microsoft Edge on some PCs and has repeated its promise of a late October fix.
Interestingly, Microsoft has not added these two issues to the official list of issues yet. We will keep you updated if users report more issues with the update KB4517389.