For what it’s worth, one thing that helped is this IS setting:
Settings > Messaging > JNDI Settings > JNDI Provider Alias
JNDI Alias Name = DEFAULT_IS_JNDI_PROVIDER
Provider URL=nsps://<HOSTNAME>:6849
Here, the HOSTNAME was using a DNS alias (DNS friendly name) to our UM server. When we changed HOSTNAME to the ‘proper’ hostname of our UM server, the problem having to restart IS after adding MWS users got resolved.
SAG support discovered this workaroung. It fixed the issue on one environment (but not the other). I haven’t progressed it, but hope it helps you.
#webMethods#user-management#Integration-Server-and-ESB