Canon EOS R5 Mark II Advanced User's Manual page 846

Note
In linked shooting, pressing the AE lock or depth-of-field preview button executes
focusing and metering just as pressing the shutter button halfway does.
Once you have established a connection between sender and receiver cameras,
the settings are retained even after changes such as replacing the batteries.
If you will no longer use a receiver camera in linked shooting, set [LinkedShot] in
[Connection settings] on the receiver camera to [Disconnect].
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