Edges sticking when BESO is used with numbers with many decimal places

I am now using the Karamba in the m-system and making full use of both the BESO beam and shell for topology optimisation. The line-to-line spacing can be around 0.003 m (3 mm). After a lot of testing, I found that if the material dimension is more than 3 decimal places, the reduced beam is off the original vertex and sticks to it at an angle, is there any way to solve this problem?
(Note 1; I don’t want to change the mm system because of the circumstances.)
(Note 2; the minimum length in the BESO component had no effect)