This flashing indicator is only visible if a network with Inventor modules is causing constant field updates. This can happen because some viewer interaction makes constant updates necessary, but may also happen if Inventor field connections form a loop and at least one ML or macro module field is involved (because that foils the loop detection of Inventor). So if this indicator is visible without any interaction, you need to investigate your network, for example by using profiling, see Section 17.2.2, “Fields”.

For a possible way to break notification loops see Section 27.5, “Using SyncFloat to Reduce System Load”.