The answer is no, it is not fixed in AC 8.1.v1 1410.
We have seen the same bug. I have instructed my staff to use the Bezier tool or arc tool.
We so rarely use the polyline tool except for contour lines on site drawings anyways. It just happened that a new drafter started to use the tool to draw the leaders to text. Thus we discovered the problem like you.
Also only seems to be an issue as a single arc. No arcs or lines before or after. Can you confirm this Rob?
Sure hope GS resolves in 8.2.
Terrence Sturm, Architect
MBP OSX 10.15.4 Quad Core Intel i7 2.2hz
AC 17 build 5019
AC 22 build 7000
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