Error when trying to update a group of setpoints

I’m getting this error below when I try to update the setpoint on a number Z-Wave TRV’s by sending the command to the group they are a member of.

This is command I’m trying to use. If I use postUpdate instead the error is not generated, the TRV’s don’t change to the requested setpoint either. I’ve also tried without the decimal point.

gRadiatorGF.sendCommand(23.0)

This is the way the group has been configured

Group:Number:Temperature gRadiatorGF <temperature>

This is the items configuration.

Number:Temperature Kitchen_LC13_Setpoint "Kitchen [%.1f °C]" <heating> (gSetPoint, gRadiatorGF) { channel="zwave:device:860eecae25:node93:thermostat_setpoint_heating" }
2021-11-09 17:18:12.654 [ERROR] [nal.common.AbstractInvocationHandler] - An error occurred while calling method 'ThingHandler.handleCommand()' on 'org.openhab.binding.zwave.handler.ZWaveThingHandler@2f557467': null
java.lang.NullPointerException: null
        at org.openhab.binding.zwave.internal.converter.ZWaveThermostatSetpointConverter.receiveCommand(ZWaveThermostatSetpointConverter.java:148) ~[?:?]
        at org.openhab.binding.zwave.handler.ZWaveThingHandler.handleCommand(ZWaveThingHandler.java:1205) ~[?:?]
        at jdk.internal.reflect.GeneratedMethodAccessor678.invoke(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
        at org.openhab.core.internal.common.AbstractInvocationHandler.invokeDirect(AbstractInvocationHandler.java:154) [bundleFile:?]
        at org.openhab.core.internal.common.InvocationHandlerSync.invoke(InvocationHandlerSync.java:59) [bundleFile:?]
        at com.sun.proxy.$Proxy5158.handleCommand(Unknown Source) [?:?]
        at org.openhab.core.thing.internal.profiles.ProfileCallbackImpl.handleCommand(ProfileCallbackImpl.java:80) [bundleFile:?]
        at org.openhab.core.thing.internal.profiles.SystemDefaultProfile.onCommandFromItem(SystemDefaultProfile.java:48) [bundleFile:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
        at org.openhab.core.internal.common.AbstractInvocationHandler.invokeDirect(AbstractInvocationHandler.java:154) [bundleFile:?]
        at org.openhab.core.internal.common.Invocation.call(Invocation.java:52) [bundleFile:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:264) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
        at java.lang.Thread.run(Thread.java:829) [?:?]