At the publisher_rt_level, the UA_String type is not supported

[sgq-chd]

Description

I'm trying to send data using publisher_rt_level. The rtLevel is set to UA_PUBSUB_RT_FIXED_SIZE. After use of UA_Server_addDataSetField function to add a UA_String type variable, perform UA_Server_freezeWriterGroupConfiguration function will prompt error.
I noticed that in the generateFieldMetaData function, if rtFieldSourceEnabled, fieldMetaData->maxStringLength is not assigned a value. Is this a future feature? Or is there something wrong with the method I'm using?

[11:34:43.791 (UTC+0800)] warn/pubsub        WriterGroup ns=1;i=3    | Writer ns=1;i=4       | PubSub-RT configuration fail: PDS contains String/ByteString with dynamic length
[11:34:43.791 (UTC+0800)] error/userland     Failed to freeze WriterGroup configuration. Error: BadNotSupported

Background Information

Used CMake options:

 cmake .. -DUA_NAMESPACE_ZERO="FULL" -DUA_MULTITHREADING=100 -DUA_ENABLE_PUBSUB=ON -DUA_ENABLE_NODESETLOADER=ON

Checklist

Please provide the following information:

• open62541 Version (release number or git tag): 1.4.0 and 1.3.9
• Other OPC UA SDKs used (client or server):
• Operating system: Ubuntu 22.04
• Logs (with UA_LOGLEVEL set as low as necessary) attached
• Wireshark network dump attached
• Self-contained code example attached
• Critical issue

[jpfr]

@andreasebner please have a look