su bash-completion isn't working since 19.04

The su bash-completiton isn't working in 19.04 or 19.10.
There is 2 files related to su bash completion in 19.10:
/usr/share/bash-completion/completions/_su
/usr/share/bash-completion/completions/su

However, I had to get the file /usr/share/bash-completion/completions/su in Ubuntu 16.04 and put it in /etc/bash_completion.d/

su USER+TAB now complete the username.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: bash-completion 1:2.8-6ubuntu1
ProcVersionSignature: Ubuntu 5.0.0-15.16-generic 5.0.6
Uname: Linux 5.0.0-15-generic x86_64
ApportVersion: 2.20.11-0ubuntu2
Architecture: amd64
Date: Sat May 25 17:51:25 2019
Dependencies:

PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: bash-completion
UpgradeStatus: No upgrade log present (probably fresh install)