Homepod mini stereo pair disconnecting from internet after update 18.4.1

I have a pair of homepod minis set up as a stero pair in my kitchen. I've previously had problems with one disconnecting from wifi periodically, but since 18.4.1 updated, they cut out simultaneously and don't reconnect - they've basically bricked themselves. They have good signal, I've changed the settings on my BT homehub router to help the upvp, and I've fully reset them