Unsolved Qt OpcUa Server Deployment Error

[Mauda]

Dear Community,

currently I am trying to cross compile a stand-alone Opc Ua Server on a Raspberry Pi4B
For Cross Compilation, I used this instruction: https://wapel.de/?p=842
My source code is based on the official waterpump example:
https://doc.qt.io/QtOPCUA/qtopcua-waterpump-waterpump-qmlcpp-example.html

My exact problem is:
The Relaese-Version of the Server does not deploy on the Raspberry Pi correctly.

After building the software, I get following error code within the error log window

/tmp/ccF0J1PW.s:-1: Error: Assembler messages:

The compiler log window shows this error description:

/tmp/ccF0J1PW.s: Assembler messages:
/tmp/ccF0J1PW.s:4206: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8
/tmp/ccF0J1PW.s:13562: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8
/tmp/ccF0J1PW.s:71648: IT blocks containing 32-bit Thumb instructions are deprecated in ARMv8

After running the Application with the error, I got the following Output in the Application Window:

Could not initialize server.
double free or corruption (fasttop)

I searched within the internet for a solution, but I couldn´t find anything.
My thougts about possible error reason are:

• wrong Raspberry Pi Development Kit

• wrong compiler is used

Is there anyone who had the same problem?
I would be glad to get any tips, how to solve this.

Thank you in Advance!