software and updates does not reopen after change of server

After you have changed server or have to reload, software and update does not stop refreshing cache and once you've force quit it, it fails to reopen. You can only open it after you have rebooted.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.23
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.6
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sat Aug 8 16:44:16 2020
InstallationDate: Installed on 2020-03-29 (131 days ago)
InstallationMedia: Ubuntu 18.04.4 LTS "Bionic Beaver" - Release amd64 (20200203.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_NG:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_NG
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: Upgraded to focal on 2020-04-25 (104 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update-manager.release-upgrades: 2020-05-05T15:30:03.382027