Niagara Launcher appearing in recent apps after latest update.

Niagara Launcher has started appearing in recent apps after the latest update. I've used it for years on this device and this hasn't happened before. I've made sure it is set as the default launcher. I've set another launcher as default, then switched back to Niagara. I've tried rebooting the phone. Nothing is clearing it up.

Steps to reproduce:

1. Wait a bit.

2. Open recent apps.