Tags slow performance

Hello there,
I have some expression tags that evaluates every second, this is to have some timers and know how much time a machine last in every state.
This is the code:

if(isNull({[.]Time_Running})
		,0
		,if	( {[.]Running}= True
						,forceQuality({[.]Time_Running}+1)
						,forceQuality({[.]Time_Running})
			)
		)

This used to work perfect but since last week it is showing a “Slow performance” message in tag diagnostic and I’m loosing information.
I don’t see anything weird on the logs, and my CPU performance is at 50%

What should I check to see if is wrong?
Note: I have ignition 7.9

Thanks in advance.