The problem is that you do have overrides in your dim styles.
These overrides may not appear in the dimstyle dialog box because you may not have used the "override"
button in this dialog box.
Possilbly you may have applied these overrides via "properties"
Use the "list" command and it will show all the overrides you've applied.
ok, it seems that we are getting closer
I did the overrides using properties panel, I can see the overrides using LIST command
but it still doesn't explain, why the dimension doesn't look like it should (with the overriden arrows)
notice, that the ISO-25 dimension was overriden the same way
So you want to have the user arrow "oblique narrow" ?
If so, in the properties palette change the user arrow back to closed filled arrow.
One this change has taken effect, change it back again to "user arrow"
A dialog should pop up that will allow you to select the user arrow block.
Select the "oblique narrow" block.