2016 foreman Rubicon PS problems

Have a 16 Rubicon that the PS light comes on and shuts off PS. Been to dealer several times and have replaced – battery/ 3 computers/ cleaned grounds / PS unit and problems still happens.. can shut off and start right back up and all is fine for a while. Any thoughts or ideas? Thanks
oh ya never been swamped or abused this is my 69 year old dad’s Atv. Only has like 300 is miles.