Hello,
The IR buttons of the new VFB are still buggy in the latest version, example during an IR session :
EDIT : it’s the IR pass limit setting that changes the button state, so not a bug, but maybe not the expected behavior for users ?!
Corona 12 update 2 hotfix 1
C4D 2025.2.1
It seems that you have pass limit set for IR, so whenever it reaches that limit, IR is stopping and the stop button becomes inactive. It’s not a bug, but a normal behaviour, although i admit it slightly irritates me when i can’t explicitly stop IR when it pauses because of pass limit.
Yeah you’re right, my bad. I’ll disable the pass limit because this thing annoy me, but I find the logic weird here : IR is still running even if Corona is not actually rendering.
We can consider this solved, right?
When IR reaches its pass limit, it is stopped. Why would you want the stop icon to be still active?
Because you want to stop IR session, but you can’t. Instead you have to wiggle the view, or resize VFB to trigger IR and then you can stop it. It’s just inconvenience.
Yep, I strongly vote for having an active “stop” button in this condition. It’s nice that it automatically starts again if some scene change occurs. But if you do not want exactly this, there is no way to stop it currently.
Good Luck
This is already logged in our ideas portal - Interactive rendering and max passes - no | Corona Ideas Portal
Cast your votes! 
Ah thanks maru, added my vote.
Imho this is a Corona glitch and should be fixed independently from user votes
Good Luck