Initial unit settings

[truth1ness]

For the longest time my PM4 would always show 500m time as the default unit. For a little while I started using watts and switched to that for a number of sessions. However, at some point my PM4 started to show watts be default whenever I started rowing. I don't remember when exactly and if I did anything in particular to reset the default unit disply. I would like it to go back to showing 500m time again by default but can't figure out how. I've been constantly setting it back to 500m time and making sure it's set to that when it turns off but it keeps going back to watts when it boots up again. How the heck do I get it to switch back?

[Citroen]

There's a big button on the bottom left side labelled [CHANGE UNITS] keep pressing it until your desired units re-appear.