3035507 - Error: No authorized routine named "NVARCHAR" of type "FUNCTION" having compatible arguments was found. SQLSTATE=42884, after making DDL changes to DB2 remote source, SDI 2.4.x

• Error: No authorized routine named "NVARCHAR" of type "FUNCTION" having compatible arguments was found.  SQLSTATE=42884, after making DDL changes to remote source
• Occured after the update of our HANA 2.0 Revision from 52 to 53 we experience different issues with some datasources connected via SDI from DB2 database.

• When searching tables on DB2 side, only the first 200 are shown when entering the '*' in the search field. If you type in some combination with normal letters (e.g. 'AB*') no table is found even if there are some beginning with AB...
• Changes of fields in datasouces cannot be activated, since the Views are not found anymore (similar to point 1)
• When extracting preview data from data source GL_TRAN_08 (source system HANASDA), the following errors come up in the HANA indexserver trace:

[31056]{214205}[27/-1] 2021-02-18 14:55:52.972380 i TraceContext     TraceContext.cpp(01269) : UserName=SAPSR3, ApplicationUserName=LANGTH, ApplicationName=ABAP:M1D, ApplicationSource=SAPLRS_GENERAL:4831, Client=001, StatementHash=86c356c4d56d0ed22c20a07963082f13, EppRootContextId=D1C7A192AFBC491E9322673F5FC760E8, EppTransactionId=19BC1C24E15742408E8E4ACE2AD51207, EppConnectionId=FDC2969071F011EBB0B9FB480A9D80B6, EppConnectionCounter=1, EppComponentName=, EppAction=, StatementExecutionID=844435514378197[31056]{214205}[27/-1] 2021-02-18 14:55:52.972354 e FedTrace         odbcaccess.cpp(03879) : ODBC error: connected: 1 state: 42884 code: -440 [IBM][CLI Driver][DB2/LINUXX8664] SQL0440N  No authorized routine named "NVARCHAR" of type "FUNCTION" having compatible arguments was found.  SQLSTATE=42884

SAP Hana 
Revision:  HANA 2.0 Revision 53
On premise: yes
Single DB: yes

Data Provisioning Agent: yes but DB2 is bound on indexserver
Version:
Operating System of DPAgent machine:
Version of JAVA used for DPAgent:
Adapter in use: DB2

KBA , HAN-DP-SDI , SAP HANA smart data integration (SDI) , Problem