Sentinel UI not showing up

Sentinel UI doesn't show up for me sometimes?

I'm not in a unique map just doing story missions in Act 7

Sentinel has charges and hasn't been used in this map yet and usually when it has the UI turns red and greys out the sentinel to show its been used.

Reloading the game doesn't help and its happened in every map from Act 7 The Crossroads, to The Crypt?

Did I accidentally push a button the remove the on screen UI or something?