Awkward behaviour with awkward time signatures

in Euclidian mode I have a 3 steps 1 fill pattern, time signature is 4/4 and polyrythmic setting. Now I am playing around changing time signatures to 5/4 and 7/4 (and other odd ratios) with same fill and step. It results that every n repetitions of the pattern there is a double note that come out. In 5/4 it happens every 19 repetitions (every 28 in 7/4). At first I was thinking about ppqn resolution or timing issues due to the use of irrational ratio, that could not make perfect division of time, but actually all the repetitions are (sounds) perfectly regular (no time drift or somthing) save the every 19th that perform a double note. Any idea about what is hapening?