WinCC RT Pro V11 SP 2 Update 5 - I/O field string bug?

When a string is written to the IOField1 (string formating set to *) the string is not accepted and the string is not written to the specified PLC tag. The same thing happens when a string is written to the IOField2 (also if the string is shorter than the specified string format, nothing happens; the string is not accepted).

When a string is set in PLC (using watch table), the string is displayed in the IOField1 but it contains some strange special characters at the end. The string is not displayed in the IOField2 (why not?).

When a string is written to the IOField3 (internal tag; string formating set to *) the string is accepted, but is not displayed in the IOField4. If a string is written to the IOField4 (the string length is the same as the set string format), the same string is accepted and displayed in the IOField3. If the string is not the same length as the specified string format, the string is not accepted and not displayed in the I/O fields.

What is strange about this is that when reading and writing strings to/from PLC using WinCC Advanced V11 SP2 everything works OK. One can read and write strings normally.

Thank You,

Igor

P.S. - the PLC (S7-1215, firmware 3.0) is directly connected to the PC (WinCC Professional V11 SP2 Update 5, WinCC Advanced V11 SP2)