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One thing to note, the Ring RE2 does appear to have some issues with power settings on range test (I.E. they don't work). I recommend not attempting to set power on the Ring for testing.
You can look in the Z-Wave Details page and look to see if the repeater is being used for the other devices you are having issues with. If it isn't in the path, then it isn't going to affect performance of those devices. It can sometimes take a long time for devices to decide to use a new path to the hub...