WhatsApp - keyboard keeps disappearing

I seem to have developed an issue over the past few days, whereby the keyboard will repeatedly disappear while I’m trying to write messages in WhatsApp.

It seems almost exclusively to happen in WhatsApp rather than any other app. Anyone else experiencing this?

My FP 5 has generally been rock solid since I bought it in January, but it feels a bit less stable since the last update.

Could you indicate

  • the current build number (Settings > About phone > Build number)
  • which keyboard you’re using