Tag quality continuously flickers from good to bad quality for AB Logix Driver V21+

Hi, I am using Ignition Platform V.7.9.8 and communicating it with Allen Bradley L73 ControlLogix PLC V.30.
Ignition has been allocated 4GB memory.
There are two different scan class for tags. First is 500ms and another is 1 sec. Tags quality on my screen continuously switches/flickers from good to bad. Sometimes, it shows-up unknown tag quality (occur very few times). Even logs doesn’t show any tag related issue.

Can someone please help me to identify what can be the issue and how we can resolve it?

Thanks in advance!

Have you looked at the load factor in the device diagnostics? What you are describing sounds a lot like simple overload.