Changing Homematic thermostat temp does not work in sitemap anymore

I have this entry in my sitemap (for use in the openHAB Android app) for my Homematic IP heating group:

Setpoint item=HM_HeizungWohnzimmer_1_SetPointTemperature label="Wohnzimmer Solltemp. [%.1f°C]" minValue=4.5 maxValue=25 step=0.5

I think since OH 3.x, when I try to change the temp, I get this exception in the log:

2022-04-16 16:53:10.976 [ERROR] [ternal.handler.HomematicThingHandler] - null
java.lang.NullPointerException: null
        at org.openhab.binding.homematic.internal.converter.type.QuantityTypeConverter.toBinding(QuantityTypeConverter.java:51) ~[bundleFile:?]
        at org.openhab.binding.homematic.internal.converter.type.QuantityTypeConverter.toBinding(QuantityTypeConverter.java:1) ~[bundleFile:?]
        at org.openhab.binding.homematic.internal.converter.type.AbstractTypeConverter.convertToBinding(AbstractTypeConverter.java:103) ~[bundleFile:?]
        at org.openhab.binding.homematic.internal.handler.HomematicThingHandler.handleCommand(HomematicThingHandler.java:338) [bundleFile:?]
        at jdk.internal.reflect.GeneratedMethodAccessor179.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.$Proxy2193.handleCommand(Unknown Source) [?:?]
        at org.openhab.core.thing.internal.profiles.ProfileCallbackImpl.handleCommand(ProfileCallbackImpl.java:80) [bundleFile:?]
        at org.openhab.core.thing.internal.profiles.SystemDefaultProfile.onCommandFromItem(SystemDefaultProfile.java:48) [bundleFile:?]
        at jdk.internal.reflect.GeneratedMethodAccessor178.invoke(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
        at org.openhab.core.internal.common.AbstractInvocationHandler.invokeDirect(AbstractInvocationHandler.java:154) [bundleFile:?]
        at org.openhab.core.internal.common.Invocation.call(Invocation.java:52) [bundleFile:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:264) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
        at java.lang.Thread.run(Thread.java:829) [?:?]

Any hints? Thanks!

Created an issue: [homematic] Changing Homematic thermostat temp does not work in sitemap anymore · Issue #12644 · openhab/openhab-addons · GitHub