When I dimension they include circles and rectangles and making a mess of everything. The dimension styles manager box shows heaps of circles and rectangles.
I would go into block editor and see if the architectural tick block (think block is called _archtick or something like that) has a circle that has been added to it by mistake.
That's my best guess, if that's not it, no idea. We have a few clients that use custom arrowheads, and have encountered similar issues when someone edits the incorrect block.
No telling on that one. Have seen autocad do some goofy things. No chance someone else worked in the drawing, or that it was modified and sent back to you by a client, etc?
All I remember is that I worked on the job for a few hours straight, dimensioning, and then had a look at another part of the job and there was a mass of circles and rectangles.
Thats when I started to pull my hair out.