While I'm playing on my phone I might switch to PC to do Arena bc it's more convenient and when I return to my phone it still has the old stats. I press sync but nothing happens. If I check on my PC and refresh the page it has the old stats too like the phone and then I have to re-do the Arena. Is there anyway to avoid/fix this?

See https://www.warzone.com/wiki/Warzone_Idle_Syncing

It sounds like you're opening Idle on multiple devices at once, which is not supported.

Also make sure you play the arena on the same device you start it on. Don't switch in the middle of the game or you won't get the reward.

What you should do to avoid this is to manually sync (CTRL + ALT + G on pc or use the sync button in the app menu) and then close the app or browser tab before switching to another device.

Also, if you are just struggling with the arenas from your phone, please note that you can start the arena game on your phone and then continue that game from pc without having to open the idle page on pc.

The MP dashboard (https://www.warzone.com/MultiPlayer/) will have all your MP games listed, including your current arena games.

Ok so I'm supposed to sync from the device I want to the stats from. I guess I was doing it backwards. I was syncing from the device I wanted to use hoping the stats would update in it.