Tr064:fritzbox stopped working after mi

Version: Openhab: openHAB 5.1.0 Release Build
Fritzbox: 7590 8.24-127389 BETA
Error: COMMUNICATION_ERROR could not get device definitions from IP

Config:

Bridge tr064:fritzbox:LocalRouter "Dev_Router" @ "TV" [ 
	host="IP", 
	user="User", 
	password="geheim", 
	backupDirectory="/mnt/onedrive/openhab/Fritz/TV/",
	timeout=5,
	backupPassword="geheim",
	tamIndices="0",
	missedCallDays="1",
	rejectedCallDays="1",
	inboundCallDays="1",
	callListDays="1",
	phonebookInterval="600"
]
{
  Thing subdeviceLan LAN "Dev_RouterLAN" @ "Tennisvilla" [ uuid="uuid:75802409-bccb-40e7-8e6b-2C91ABFFC10A",
    macOnline=
	"C4:5B:AC:30:92:F6", // iPhone 
	"9C:DA:A8:D4:8F:E9" // 2nd iPhone
 ] 
 Thing subdevice WAN "Dev_RouterWAN" @ "Tennisvilla" [ uuid="uuid:75802409-bccb-40e7-8e6a-2C91ABFFC10A"]
 Thing subdevice WANCon "Dev_RouterWANConnection" @ "Tennisvilla" [ uuid="uuid:75802409-bccb-40e7-8e69-2C91ABFFC10A"]
}

After upgrading from openHAB 4.3.9 to 5.1.0 the binding stopped working.

Some errors after trying to restart the bridge:

2026-01-06 10:59:37.446 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : ServiceFactory.getService()
2026-01-06 10:59:37.448 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : This thread collected dependencies
2026-01-06 10:59:37.448 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : getService (ServiceFactory) dependencies collected.
2026-01-06 10:59:37.449 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : Querying state satisfied
2026-01-06 10:59:37.450 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : For dependency osgi.ds.satisfying.condition, optional: false; to bind: [[RefPair: ref: [{org.osgi.service.condition.Condition}={service.id=6, service.bundleid=0, service.scope=singleton, service.pid=0.org.osgi.service.condition.ConditionImpl, osgi.condition.id=true}] service: [null]]]
2026-01-06 10:59:37.451 [DEBUG] [nding.tr064.internal.FritzboxActions] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.FritzboxActions(393)] : Changed state from satisfied to active
2026-01-06 10:59:37.488 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : ServiceFactory.getService()
2026-01-06 10:59:37.495 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : This thread collected dependencies
2026-01-06 10:59:37.495 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : getService (ServiceFactory) dependencies collected.
2026-01-06 10:59:37.495 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : Querying state satisfied
2026-01-06 10:59:37.496 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : For dependency osgi.ds.satisfying.condition, optional: false; to bind: [[RefPair: ref: [{org.osgi.service.condition.Condition}={service.id=6, service.bundleid=0, service.scope=singleton, service.pid=0.org.osgi.service.condition.ConditionImpl, osgi.condition.id=true}] service: [null]]]
2026-01-06 10:59:37.497 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : invoking activate: activate: parameters [org.apache.felix.scr.impl.helper.ReadOnlyDictionary]
2026-01-06 10:59:37.497 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : invoked activate: activate
2026-01-06 10:59:37.498 [DEBUG] [tr064.internal.Tr064DiscoveryService] - bundle org.openhab.binding.tr064:5.1.0 (306)[org.openhab.binding.tr064.internal.Tr064DiscoveryService(395)] : Changed state from satisfied to active
2026-01-06 10:59:37.734 [DEBUG] [hab.binding.tr064.internal.util.Util] - Unmarshalling failed: null

When AVM updated their firmware about 2-3 months ago, it totally broke my VOIP; therefore I have a strong (but not proven) suspicion that they may have broken some other things like tr064 as well. In the meantime I changed to another VOIP supplier..