I thought it would be nice to have the CPU load displayed along with the new mixer screen but when I turn it on, the red “!” Xrun symbol flashes about once a second regardless of load. There are no audible artifacts, just the flashing symbol.
This even happens with the Zynthian idling with no chains selected at all. I have some load tests that I threw together that don’t show any Xruns or any other status issues at all. But they also show Xrun symbol flashes with the CPU Load display enabled.
It smells like a bug, but i can reproduce it, sorry 
Me too,I meet this phenomenon for a long time.But it have no influence on the audio, no click or noise,just blink the red "!"sign.
Hmm… Well now I can’t reproduce it either! 
I wondered if it had something to do with my USB audio hardware. My V3 RBPi4 kit obviously has the HiFiBerry ADC+DAC but I have been using my external EMU 0202 USB as the output recently because it’s also very clean and has a nice headphone amp on it.
I switched back to the HiFiBerry ADC+DAC and added the CPU Load display. There were no flashing XRun symbols.
I then switched back to the EMU 0202 and again, no flashing XRun symbols.
Weird. I didn’t imagine it, really I didn’t! 
If and when it happens again, I will post info.
Are you sure it was the xrun exclamation symbol and not the over temperature or under voltage symbol?
I was always campaigning for all these symbols be different colours so they could be displayed on one RGB LED, and to differentiate them in situations like this.
As you can see I have a shoehorn for just these sorts of occasions.
Yup. That was my first thought so I double checked. It’s the exact same trangle “!” symbol that flashes when you load a new snapshot for instance.
Also, I added a fan so my system rarely breaks 60 F and I have a nice, stable 3.5A USB supply and I’ve never seen voltage warnings.
IMO, different warning symbol colors would be helpful as they are rather small on a standard Zynthian display.
I tried this on my headless RBPi3 this morning. No flashing XRuns.
Who knows what happened yesterday.
If it’s actually a bug it will surface again. On the other hand, if I’m losing my mind and hallucinating I may just have to set all this technical stuff aside and go into politics where the mindless seem to thrive.
There is a fix for that…