Second display resolution changing randomly on M1 MBP

Hi,

I've got a M1 MacBook Pro connected to a CalDigit TS3 dock via Thunderbolt 3 which is, in turn, connected to a BenQ PD2720U Display via Thunderbolt 3.

I have to have the resolution on the second display set to scaled because if I set it to default it's simply too big and doesn't take advantage of the 4K resolution (no idea why this is, but that might be another question).

Problem I have is that randomly and quite often when I wake the MacBook from sleep the second display resolution has changed and things like the dock are enlarged and disappear off the screen. To fix it I have to open the display settings, change it back to default and then change it back to the scaled setting that it looks best at.

Anyone got any thoughts about how I can fix this?