TDEngine 3.3.4.8: Problem running UDFs

Bug Description
We're experiencing a problem when running UDFs in our TDEngine instance, version 3.3.4.8. The problem is as follows.
When trying to run an UDF, we getting the error in the image.

I've checked the logs from the /var/logs/udfdlog.0:

2/07 14:36:46.555687 01165474 C UDF setup request. seq num: 9, udf name: fibonacci
02/07 14:36:46.555713 01165474 C UDF udfd expired, check for new version. existing udf fibonacci udf version 0, udf created time 0
02/07 14:36:46.555996 00000137 C UDF ERROR udfd rpc error. code: Sync leader is unreachable
02/07 14:36:46.556013 01165474 C UDF ERROR can not retrieve udf from mnode. udf name fibonacci

The mnodes are ok:

The querying functionalities are working as expected.

The only problem we're experiencing is the one with the UDFs.

I've deleted the UDF and created again, nothing worked.

To Reproduce
Not very easy to reproduce.

Expected Behavior
UDF properly working.

Environment (please complete the following information):

• TD 3.3.4.8