refresh_interval does not exist in OH2. It has been replaced with the Polling Interval configured on the Thing. Rremove this from your Items. However, your items should be updating without the need to rely on the polling. I do not have this device, but it appears that your items do need some updating. Hopefully someone with this device will chime in. My understanding is that you would not use the channels in Endpoint 0. You could start here…
https://community.openhab.org/search?q=fgd212%20order%3Alatest
This is a bit of a guess, but I think your items should look something like this (note: I used code fences to improve the appearance). Why do you have separate items for Homebridge and the switch? I think you can combine these all into one item.
Switch MBed1 “MasterBed Reading” (FiF_MBed) { channel=“zwave:device:c684afb6:node27:switch_dimmer1” }
Dimmer MBed1_dim “MasterBed Reading [%d %%]” (FiF_MBed, fDimm) { channel=“zwave:device:c684afb6:node27:switch_dimmer1” }
Dimmer MBed1_HB “MasterBed Reading” (Homebridge) [ “Lighting” ] { channel=“zwave:device:c684afb6:node27:switch_dimmer1” }
Number MBed1_alarm “MasterBed Reading - Alarm” (fAlarm) { channel=“zwave:device:c684afb6:node27:notification_send1” }
Number MBed1_power “MasterBed Reading - current power consumption [%.2f W]” (gEnergy) { channel=“zwave:device:c684afb6:node27:meter_watts1” }
Number MBed1_energy “MasterBed Reading - total energy use [%.2f KWh]” (gEnergyKWh) { channel=“zwave:device:c684afb6:node27:meter_kwh1” }
There’s no need to delete the Thing for the controller, or to delete the Items. Just delete the Things and rediscover. This should only be needed after updating a binding where there are channel updates that have been made for devices that you already have a Thing for. After reading through the whole thread, I do not think this is your problem. Just be aware of it when you are updating bindings. There have also been some recent breaking changes in 2.3, which may make certain 2.3 bindings imcompatible with previous versions of OH2. If strange things happen (specifically during discovery), you may need to upgrade OH to 2.3 snapshot to use a 2.3 binding.
Another consideration is to use the development zwave binding. It should be the same as the 2.3 snapshot, as far as devices go, but has many features and fixes in it.