Haha.. Thats just over 1 ohm on those spikes.. Seems to be too little for 8kHz sampling errors. In temperatures it would be something like 0.002 degrees ;)
So, you’re hunting ghosts ;)
You could set bigger sample size.. App seems to offer 125Hz/64smpl (with resistance & internal temp selected), set samples manually to 256 and it should mostly smooth out. It does update much slower though, but temperatures would not change that fast and there will always be some delay in your probe etc, so it would not do any harm.
Zooming out would help also.. Your whole screenshots range is now ~0.01 degrees :D