See https://github.com/openhab/openhab-core/pull/2986
TL;DR: openHAB introduces a change in 3.3.0: events subscription URL must be explicitly set as a regexp.
ie. changing from
/rest/events?topics=openhab/items" to
/rest/events?topics=openhab/items/*"
Makes also optional authentication truly optional by checking username/password settings
See https://github.com/openhab/openhab-core/pull/2986 TL;DR: openHAB introduces a change in 3.3.0: events subscription URL must be explicitly set as a regexp. ie. changing from /rest/events?topics=openhab/items" to /rest/events?topics=openhab/items/*"
Makes also optional authentication truly optional by checking username/password settings