WinCC issues

I recently encountered screen glitches and subsequent manual controls issues on an automated blanking line. The CPU is a Siemens s7-300 and the HMI is a PC running WinCC RT v7.2. I have posted pictures here. I have had some experience with the exclamation points in that I/O feedback did not match the field conditions. In this instance, I can find no discrepancies. The "Operator Enable at P2" will toggle between high (green) and low (red) and the exclamation points will come and go as well. When I monitor the function that controls the Operator Station Enable (there are three HMIs that access these controls) online with Simatic Step 7, there are no bits changing and the station enabled will be correct in all instances. There are multiple manual controls for separate devices and this is the only entity displaying this condition. Can someone explain the exclamation points and the small icon on the "Safety OK" and the "Enable - no external fault" conditions? I am fairly green with this WinCC stuff.

There is a WinCC integrated function to show when the variable status goes bad with the exclamation mark and do this style of underlying grey behind an animated output.
If this is not a custom function, then the variable status goes bad if the conection to the plc is lost (e.g. network problems) or wasn't started yet, or the variable read request was not successfully answered by the plc (e.g. desired address not available, which could here not the problem as the status ok comes back).

You should take a look into the WinCC logfiles in the diagnose directory of the WinCC installation directory. Interesting is here especially the logfile of the S7 channel.