Niteq Duo acting wonky

I did a dive this week on one of our local spots. It was out first dive of the day and my Max Depth was 99 feet. My back gas was 32% nitrox with a deco gas of 50% Nitrox. Both values were properly entered in my computer before the dive. I did not even come close to exceeding my NDL since the group I was with included some air hogs and ended up ascending when they got low. I completed my gas switch at 50 ft and continued a extremely slow assent. When I arrived at 20 Feet where the computer normally indicates a safety stop, it started wigging out. It was jumping from the actual depth to 10 feet or 0 feet and back to 20 feet. It was doing this every two or three seconds causing the alarm to constantly go off and the "STOP" indicator to constantly flash. Surface conditions were absolutely calm with no waves. Luckily I was wearing a backup computer and followed it with no issues. Upon arriving at the surface, it properly recorded the SI. I completed the second dive (shallow reef, max depth 30ish feet) with no issues. Used the secondary computer but took the Duo to see if it would act up. It did not on this dive. Anyone have a thought on why the computer might have done this on the first dive?

My older one did that on a few occasions, but I can't remember if I found a correction before the computer was stolen. I have a "new" Nitek Duo and it hasn't wigged out like that.