Dear Otared, Thank you for checking my code.
The strange fact is that if one puts \startitem $\overline{A} = A$ \stopitem as the first item in your example (instead of the second), then ConTeXt creates three columns, with the first item the result of the above line, and then items 2 and 3 in the second column and finally item 4 in the third column. Despite this the textwidth is divided into four…
I have noticed before what you described. If there are 8 items, the outputs are all different depends on the location of \overline. I couldn’t see any pattern in the output. The only thing I can see is that the command ‘\overline’ makes a blank line, and I just guess that it is related with the column environment.
I hope Hans will see your message and fix the issue.
Yes, it is also my hope. And, I believe that he also solve the alignment problem too. Best regards, Dalyoung