mDNS local names stop working after network outage

Hi All,
There seems to be an issue when the network is dropped and then recovers, i.e. cable unplugged or router restarted.
steps to reproduce:

  1. start Homeassistant
  2. access homeasistant.local via a web browser works fine, ping homeasistant.local also works
  3. Switch router off and on gain, or unplug and re plug network cable
  4. homeasistant.local no longer resolves and access is lost.

There seems to be an issue with handling the network reconnection.
Has anyone seen this and is there a workaround?

Thank you for any help,
Chris.