I got this error in my HA os.
Login attempt or request with invalid authentication from localhost (127.0.0.1). (Mozilla/5.0 (iPhone; CPU iPhone OS 14_4_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Home Assistant/2021.4.1 (io.robbie.HomeAssistant; build:2021.115; iOS 14.4.2) Mobile/HomeAssistant, like Safari)
What am i supposed to do?
There are several threads about this sort of thing (do a search). Lots of ideas but no universal answer. Most of us ignore it, and it doesn’t go away. 
Yep, issue being persisting for at least 3 years. No fixes. Many users effected (probably double digit %). Every update I hope it’s resolved. Instead we get new icons for entities and other way more important things. 