[1.2.2] Strut ends refuse to attach to certain places, jump to elsewhere.

[MilkSage]

[ KSP 1.2.2 + RSS + SMURFF ]

When building tall rockets in the VAB, we need struts to reduce wobble.   Sometimes it works nicely, struts attach perfectly with symmetry 4,6 or 8. At other locations, strut ends seem to refuse to attach even after repeated attempts and varying the locations slightly.  And even when doing individually (no-symmetry). 

Usually the first strut end stays in place, while the second strut end jumps to somewhere else, either shorter or longer.

Is this a known bug that I just have to live with?

[Gargamel]

Post some screenshots so we can see what you are doing exactly.

Sometimes struts don't like what they are being attached to (fairings for example), and will jump to another module.   Also, if there is an object in the way between the two ends of the strut, they will often link to the object, and not your intended target.