Construction Line Placement

[MHDCAD]

I've been using some version of AutoCAD for 20 years or so.  I use construction lines on a regular basis.  Since my company updated to the new (to us) version of civil 3D my construction lines work funny.  Sometimes they place like I am used to - Click one point, then click another point and get a straight line.  And sometimes when I click a point, they just go to a seemingly random rotation and they are fixed there.  Then I can click to place. I'm sure there is some kind of setting but I can't figure it out. 

I've uploaded a short clip.  The first two lines I make work the way I want.  I click a point then click a second point.  The third line is where it acts funny.  Not sure what is going on.  What am I doing wrong?

[brian.strandberg]

Not sure I understand the issue - it looks like the first two lines go in as expected.  I wonder if on the 3rd its dropping into the bisect option which can be unpredictable, but I didn't see you call for that option.

Can you post the drawing you were using?  Curious if there is something there.

[MHDCAD]

It seems like it often happens if I start my construction line from an endpoint of a line. I can't post the exact file, but I made a test file that seems to work the same for me.  When I click anywhere in the drawing using a construction line I can make one as expected, unless I start from the endpoints. Then it starts snapping to random angles. 

[MHDCAD · Accepted solution]

It looks like maybe it has to do with osnaps.  I was doing some more googling and I found someone that had a similar type issue.  A suggestion was to turn the perpendicular osnap off. I tried that and now it seems to be working normal.  I'll keep testing. 

This could be the issue, as I have been drawing with the perpendicular osnap turned on by default and I didn't used to do that.